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Clinical Abstracts
Clinical Abstracts on Transesophageal Atrial Pacing during Echocardiography Exams
Transthoracic stress echocardiography with transesophageal atrial pacing for bedside evaluation of inducible myocardial ischemia in patients with new-onset chest pain. Atar S, Cercek B, Nagai T, Luo H, Lewin HC, Naqvi TZ, Siegel RJ. Department of Medicine (Division of Cardiology), Los Angeles, California, USA. Am J Cardiol 86(1):12-16, 2000. To date, there are no data on the feasibility and accuracy of bedside pacing stress echocardiography in patients admitted to the hospital with new-onset chest pain or unstable angina. We evaluated the feasibility of pacing stress echocardiography and examined its correlation with myocardial perfusion stress scintigraphy (rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion single-photon emission computerized tomography) performed within 24 hours of the pacing stress echocardiography test. We studied 70 consecutive patients after acute myocardial infarction had been excluded. The bedside pacing stress echocardiography test was performed with 10Fr transesophageal pacing catheters. We found pacing stress echocardiography to be feasible and safe (3% minor adverse event rate) at the patients' bedside. Target heart rate of >85% of the age-predicted heart rate was achieved in 96% of patients, and the mean rate-pressure product was 22,644 +/- 4,520 beats/min/mm Hg. The mean duration of the bedside pacing stress echocardiography test including technical preparations and image interpretation was 41 +/- 7 minutes. Pacing stress echocardiography and myocardial perfusion stress scintigraphy correlated well for identification or exclusion of inducible myocardial ischemia in 63 of 70 patients (90%) (kappa 0.81, p <0.001). The extent of inducible myocardial ischemia by vascular territories correlated with myocardial perfusion stress scintigraphy in 52 of 70 patients (74%) (kappa 0.6, p <0.001). We conclude that bedside pacing stress echocardiography is feasible and safe, and highly correlates with myocardial perfusion stress scintigraphy for identifying inducible myocardial ischemia in patients with new onset of chest pain or unstable angina.
Nonexercise stress transthoracic echocardiography: transesophageal atrial pacing versus dobutamine stress. Lee CY, Pellikka PA, McCully RB, Mahoney DW, Seward JB. Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Mayo Foundation. J Am Coll Cardiol 1999 Feb;33(2):506-11. OBJECTIVES: To compare transesophageal atrial pacing stress echocardiography with dobutamine stress echocardiography for feasibility, safety, duration, patient acceptance and concordance in inducing wall motion abnormalities. BACKGROUND: Transesophageal atrial pacing is an effective method of increasing heart rate and has been used in the assessment of coronary artery disease. METHODS: Both tests were performed in sequence on the same patients in random order. Transesophageal atrial pacing stress echocardiography began at a heart rate of 10 beats/min above the baseline value and was increased by 20 beats/min every two min until 85% of the age-predicted maximum heart rate or another end point was reached. Dobutamine echocardiography was performed using three-min stages and a maximum dose of 40 microg/kg per min. Atropine (total dose <or =2 mg) was administered at the start of the 40 microg/kg per min stage if needed to augment heart rate or during pacing if Wenckebach heart block occurred. RESULTS: Transesophageal atrial pacing stress echocardiography was feasible in 100 of 104 patients (96%); the duration (8.6+/-3.6 min) was significantly shorter than that of dobutamine stress echocardiography (15.1+/-3.9 min) (p = 0.0001). With transesophageal atrial pacing stress echocardiography, the recovery period was shorter, symptoms and dysrhythmias were fewer, hypertension and hypotension were less common and target heart rate was more frequently achieved. No complications occurred with either test. Patient acceptance was satisfactory. Agreement between results of both tests was good for segmental wall motion scoring with a 16-segment model, scores 1 to 5 (kappa: rest, 0.79; peak, 0.57) and test interpretation (normal, ischemia, infarction or resting wall motion abnormality with ischemia) (kappa: 0.77). CONCLUSIONS: Transesophageal atrial pacing stress echocardiography is a feasible, well-tolerated alternative to dobutamine stress echocardiography. It can be performed rapidly and shows good agreement with dobutamine stress echocardiography in the induction of myocardial ischemia.
Accuracy and usefulness of atrial pacing in conjunction with transesophageal echocardiography in the detection of cardiac ischemia (a comparative study with scintigraphic tomography and coronary arteriography). Don Michael TA, Rao G, Balasingam S. Kern Medical Center, Los Angeles. Am J Cardiol 1995 Mar 15;75(8):563-7. A comparative study of transesophageal echocardiography with single-photon emission computed tomography (SPECT) and coronary arteriography was performed in a community outpatient setting to determine accuracy and feasibility of the technique. Forty-one of 55 patients underwent all 3 procedures within a 90-day period. Fourteen patients underwent only SPECT and were compared with transesophageal echocardiography with pacing (TEEP). Atrial esophageal pacing was performed with transesophageal echocardiography to increase double product and induce ischemia, which would manifest as abnormal wall motion. The results in these patients indicated a sensitivity and specificity of 92% and 87% for TEEP and 96% and 82% for SPECT, respectively, using angiography as the gold standard. In 14 patients, the sensitivity of TEEP using SPECT as standard was 80% and the specificity was 87%. The 1 view that appeared to pick up the highest yield of abnormalities was the transgastric short-axis view. Thus, TEEP is indicated in the detection of chronotropically incompetent patients and those unable to exercise whose transthoracic images are not optimal. It is highly accurate compared with angiography or SPECT.
Accuracy and usefulness of atrial pacing in conjunction with transthoracic echocardiography in the detection of cardiac ischemia. Don Michael TA, Antonescu A, Bhambi B, Balasingam S Central Cardiology Medical Clinic, Los Angeles. Am J Cardiol 1996 Jan 15;77(2):187-90. Transthoracic echocardiography combined with transesophageal atrial pacing was performed in a community outpatient setting and compared with single-photon emission computed tomography (SPECT) and with coronary arteriography to determine the accuracy and usefulness of the technique. Two groups were defined: group A consisted of 65 of 189 patients who underwent all 3 procedures within a 90-day period; group B consisted of 53 patients who had atrial pacing with transthoracic echocardiography. Seventy-one patients had previously undergone atrial pacing with simultaneous transesophageal echocardiography. Atrial pacing to induce abnormal wall motion as an indicator of ischemia was performed by increasing the double product to > 20,000. We obtained a sensitivity and specificity of 87% and 88% for group A and 72% and 80% for group B, respectively. We believe that transthoracic echocardiography with atrial pacing is indicated as a means of stress echocardiography in its own right, especially in nonambulatory and chronotropically incompetent patients, as well as in the presence of an ambiguous result on SPECT testing. It is highly accurate compared with our previous study with atrial pacing and simultaneous transesophageal echocardiography, better tolerated, more easily accepted, less invasive, and less costly. Thus, it is a useful stress modality in the detection of myocardial ischemia.
Transesophageal atrial pacing stress echocardiography: Comparison with dobutamine stress echocardiography: Patient tolerance, safety, and hemodynamics. Pellikka P (Mayo Clinic), Lee CY (Singapore Heart Centre), Seward JB (Mayo). Circ. Suppl. #96, Abstr 196. Am. Heart Assoc, 1997. Transthoracic stress echocardiography performed with a transesophageal atrial pacing (TAP) catheter has been proposed as an alternative method of stress echocardiography. In this prospective study, patients (pts) underwent both TAP and dobutamine stress echocardiography (DSE). We compared the tests' safety, patient tolerance, duration, hemodynamics and concordance in inducing wall motion abnormality (WMA). Methods: Pts underwent DSE and TAP consecutively and randomly on the same day. TAP was performed using a bipolar pacing and recording catheter in a flexible 18 Fr Sheath (CardioCommand). Pacing was initiated at 10 beats/min above resting heart rate and increased 20 beats/min every 2 mins until target heart rate or another endpoint was reached. DSE was performed using a standard protocol. DSE and TAP results were read blindly. Pts graded both tests for comfort and acceptability. Rest and peak cardiac output were assessed by Doppler during DSE and TAP. Results: TAP was feasible in 100 of 104 pts (96%). TAP studies were significantly shorter 8.5+/- 3.6 vs 31+/- 9 min, p < .0001) and were associated with less symptoms, dysrrhythmias, and hypertensive or hypotensive endpoints. Target heart rate was more often achieved with TAP (94% vs 82%, p < .0001). No complications occurred with either test; mean acceptability scores were similar. Mean cardiac output at peak stress was greater with DSE (10.4 +/- 2.8 vs 8.6 +/- 8.25 l/min, p < .0001). There was good concordance of wall motion changes between DSE and TAP, examined in 2 ways: (1) Presence of inducible WMA (kappa-0.71); (2) Diagnosis summary (normal ischemia, infarct, or peri-infarct ischemia) in each coronary artery distribution (kappa for LAD=0.72, RCA=0.74, LCX=0.65). Order of tests did not affect concordance of results. Conclusions: Transesophageal is comparable to DSE for the diagnosis of ischemic heart disease. TAP is safe and well tolerated. The principle advantages of TAP are reduced time and effort of the procedure.
High feasibility and excellent safety of the Echo pacing stress test on a large series of patients with known or suspected coronary artery disease. Gallo A., Anselmi M., Golia G., Gaspari MG, Marino P, Vitolo A, Zardini P, University of Verona, Verona Italy. Abstract 1530, 1997 American Heart Assoc. The accuracy of the transesophageal echo-pacing test (EP) in the detection of coronary artery disease has been demostrated; however, its safety has not been investigated in large series of patients (pts). Methods: we evaluated our 6 year experience in 902 EP perforrned on 874 pts (707 males, age 58 +/- 9 years). Indications to EP were: evaluation of chest pain (42%), risk stratification after myocardial infarction (51%) and miscellaneous (7%). Regional wall motion abnormalities (WMA) were present at baseline in 62% of pts. EP were started at 110 beats/min and increased every 2 minutes by 10 beats/min. Results: EP was not feasible in 24 tests (3%), due to intolerance of the patient (11) or to impossibility to obtain a stable atrial capture (13). It was diagnostic in 838 (93%) tests (achieved 85% of the maximum predicted heart rate in 784, early appearance of large WMA in 54). EP was prematurely interrupted and not diagnostic in 40 (4%) tests because of second degree AV block type I resistant to administration of atropine 1 mg i.v. (34), hypertension (2), hypotension (2) and arrhythmias (2). Ischemia (either WMA or ST segment depression) developed in 289 tests (33%). There were no major complications (death, myocardial infarction, life-threatening arrhythmias). Minor complications (15) were: transient arrhythmias [3 atrial fibrillation, 4 PSVT, 2 atrial ectopic rhythm, 1 sinus arrest (6 sec), 3 nonsustained ventricular tachycardia (max 6 beats)], 1 mild heart failure secondary to ischemia requiring i.v. diuretics and 1 epistaxis. Conclusion: EP appears a high feasible and very safe test in the evaluation of pts with coronary artery disease. Its safety should be considered in comparison with pharmacological stressors, that have higher potential risk.
Detection of myocardial ischemia by transesophageal echocardiographically determined changes in left ventricular area in patients undergoing coronary artery bypass surgery. Hogue CW Jr, Davila-Roman VG. Department of Anesthesiology, Washington University School of Medicine, St. Louis. J Clin Anesth 1997 Aug;9(5):388-93 STUDY OBJECTIVE: To evaluate left ventricular (LV) dimensions and function during myocardial ischemic episodes in anesthetized patients undergoing coronary artery bypass surgery. DESIGN: Prospective, nonrandomized study. SETTING: Large, medical school-affiliated tertiary-care medical center. PATIENTS: 36 adults undergoing elective primary coronary artery bypass surgery. INTERVENTIONS: Transesophageal atrial pacing for 3 to 5 minutes at heart rates (HRs) of 65, 70, 80, and 90 beats per minute. MEASUREMENTS AND MAIN RESULTS: Arterial, pulmonary artery, and venous pressures, transesophageal echocardiographic (TEE) determined LV end-diastolic (EDA) and end-systolic (ESA) areas, and fractional area change (FAC = [FDA-ESA]/EDA). Myocardial ischemia determined as at least 1 mm ST segment deviation at J + 60 milliseconds from 12-lead electrocardiography (ECG) and TEE detected new LV regional wall motion abnormalities. Biplane TEE images were recorded on videotape, and LV EDA and ESA were determined with planimetry from images of the LV short axis. Myocardial ischemia was observed in 12 patients. In these patients, EDA and ESA were higher and FAC lower than those patients without ischemia at the same HR. There were no differences between patients with and without myocardial ischemia with regard to pulmonary artery occlusion pressure, stroke volume, or other hemodynamic variables. The positive predictive values were best for ESA (67%) and EDA (58%), and least for FAC (18%). Negative predictive values were highest for ESA (85%) and EDA (80%), and least for FAC (47%). CONCLUSIONS: In anesthetized patients undergoing coronary artery bypass surgery, myocardial ischemia observed during atrial pacing results in increases in LV dimensions and decreases in FAC compared with values in patients without ischemia. These results support further investigations of the clinical usefulness of monitoring LV EDA and LV ESA with TEE as a method of myocardial ischemia detection.
The importance of stress-induced cardiac wall motion abnormalities in the evaluation of drug intervention. Iliceto S, Caiati C, Tota F, Rizzon P. Institute of Cardiovascular Diseases, University of Bari-Policlinico, Italy. Drugs 43 Suppl 1:33-6, 1992. Stress-induced wall motion abnormalities are a sensitive marker of myocardial ischaemia. Stress echocardiography has recently been the subject of increasing interest because of its improved feasibility and compatibility with new and effective alternative stresses. Transoesophageal atrial pacing (TAP) with 2-dimensional echocardiography (2-D echo) is a recently developed echocardiographic stress procedure that has been shown to be reliable and effective in both the diagnosis and evaluation of stress-induced myocardial ischaemia. TAP with 2-D echo was performed after treatment with placebo and intravenous gallopamil 0.03 mg/kg in 12 patients with stable, reproducible angina of effort. Compared with placebo, gallopamil treatment increased the time to 1 mm ST-segment depression (6.6 vs 5.3 minutes; p less than 0.05) and improved the ventricular wall motion score at a heart rate of 130 beats/min (17 vs 15; p less than 0.01) and 150 beats/min (13 vs 11; p = 0.07). Three patients who developed angina after placebo administration were symptom-free after gallopamil. Thus, gallopamil exerts a beneficial effect on atrial pacing-induced ischaemia, by increasing the pacing time to the ischaemic threshold and reducing the extent of dysfunctional myocardium during ischaemia.
Quantitative assessment of transient left ventricular asynergy in coronary artery disease. Laucevicius A, Berukstis E, Kosinskas E, Jablonskiene D, Ivaskeviciene L. Vilnius University, USSR. Clin Cardiol 1991 Feb;14(2):105-10. The purpose of this study was to determine the diagnostic value of quantitative two-dimensional echocardiography during transesophageal atrial pacing in assessing the presence and severity of coronary artery disease. Apical four- and two-chamber views were registered at rest and at different pacing rates. Computerized quantitative evaluation of left ventricle wall motion was performed. On the basis of left ventricle wall motion analysis data of 22 individuals with no coronary pathology, as assessed by angiography and with negative exercise ECG and transesophageal atrial pacing ECG test, nomograms for assessment of wall motion abnormalities and for calculation of asynergy area as a measure of wall motion abnormality extent were obtained. The method revealed new transient wall motion abnormalities during pacing or exacerbation of old ones present at rest in 83 of the 89 patients with angiographically proven coronary artery stenosis greater than or equal to 70% and in 3 of the 32 controls with no changes in their coronary angiograms. Thus, it showed high sensitivity (93%), specificity (91%), predictive value of positive result (96%), predictive value of negative result (83%), and efficiency of the test (93%). These values appeared to be higher than those calculated for transesophageal atrial pacing ECG, recorded simultaneously with echocardiographic images (81, 87, 95, 62, and 83%, respectively) and for exercise ECG test which was performed in 66 coronary patients and in 29 controls (68, 86, 92, 54, and 74%, respectively). The extent of pacing-induced left ventricular regional wall motion abnormalities appeared to be directly correlated to the extent of coronary artery disease.
Transoesophageal pacing echocardiography for detection of restenosis after percutaneous transluminal coronary angioplasty. Hoffmann R, Kleinhans E, Lambertz H, Flachskampf FA, Uebis R, Buell U, Hanrath P. Aachen, Germany. Eur Heart J 1994;15(6):823-31. Non-invasive documentation of restenosis after successful percutaneous transluminal coronary angioplasty (PTCA) remains a problem. Thus, transoesophageal pacing echocardiography (TPE) with simultaneous rapid atrial pacing via the same probe, a recently validated method for detection of coronary artery disease, was used in 60 patients for detection of restenosis after successful PTCA (54 patients with one and six patients with multivessel PTCA). The patients came for routine follow-up angiography 5.4 +/- 3.7 months after PTCA regardless of clinical status. Restenosis (diameter stenosis > or = 50%) was demonstrated in 22 patients. Disease progression in previously normal vessels was noted in three additional patients. Results for detection of restenosis and disease progression were compared to exercise ECG and in 40 patients to Tc-99m methoxy-isobutyl-isonitrile (MIBI)-radionuclide perfusion imaging. Diagnostic standard exercise ECG could be performed in only 38 patients, due to peripheral vascular disease, joint disease or premature exhaustion in the rest of patients. TPE was non-diagnostic in two patients due to ineffective pacing or patient discomfort. Sensitivity of TPE for detection of restenosis and disease progression after PTCA was 84% compared with 50% and 86% for exercise ECG and Tc-99m MIBI-SPECT (P < 0.03 and ns), respectively. Specificity of TPE (85%) was also higher than that of exercise ECG (59%, P < 0.03) and comparable to the specificity of MIBI-SPECT (84%). Overall accuracy of TPE was far superior to exercise ECG and similar to MIBI-SPECT (84% vs 54% and 85%) (P = 0.0007 and ns, respectively).
The importance of two-dimensional echocardiography in conjunction with transesophageal stimulation of the left atrium for the diagnosis of myocardial ischemia. Gawor Z, Markiewicz K, Cholewa M. Kardiologischen Klinik des Instituts fur Innere Medizin, Medizinischen Akademie Lodz. Z Gesamte Inn Med 1989 Dec 15;44(24):736-40. In 27 patients with coronary heart disease (group 1) and in 15 persons of ontrol group (group 2) transoesophageal left atrial pacing was performed. 12-lead ECG and two-dimensional echocardiography were done before and on the peak of the pacing. Changes of ST-segment (ST) and R-wave amplitude of V5 in the ECG (RV5) were analyzed. Left ventricular wall motion in the 11 segments and left ventricular enddiastolic volume index (LVEDVI), left ventrivular endsystolic volume index (LVESVI), stroke volume index (SVI), cardiac index (CI) and ejection fraction were studied by echocardiography. Sensitivity, specifity and predictive value confirming and excluding of coronary heart disease of the analyzed parameters were determined. During the analysis of ST-segment these values were 0.81, 0.67, 0.81 and 0.67 respectively. Diagnostic values of the analysis of the left ventricular wall motion and the ejection fraction were not statistically different (p > 0.05) from the analysis of ST-segment. During the analysis of LVEDVI, LVESVI, CI sensitivity of the transoesophageal atrial pacing was decreased and specifity was increased (p < 0.05). The greatest value in the diagnosis of myocardial ischaemia during the two-dimensional echocardiography combined with transoesophageal left atrial pacing has the finding of the segmental asynergy of systole, diminution of EF and augmentation of LVESVI.
Comparison of postexercise and transesophageal atrial pacing two-dimensional echocardiography for detection of coronary artery disease. Iliceto S, D'Ambrosio G, Sorino M, Papa A, Amico A, Ricci A, Rizzon P. Am J Cardiol 1986;57(8):547-53. Two-dimensional (2-D) echocardiography during transesophageal atrial pacing (TAP) was recently proposed as an alternative to exercise 2-D echocardiography for the diagnosis of coronary artery disease (CAD). To compare these 2 methods, 78 consecutive patients with good-quality echocardiographic (echo) examinations at rest were studied. Two-dimensional echocardiography was performed immediately after supine bicycle exercise and at peak atrial pacing obtained with transesophageal atrial stimulation. Twenty patients were excluded: 16 because of poor quality of 2-D echo images after exercise and 4 because of inadequate TAP studies (atrial capture not achieved in 2 and intolerance in 2). Of the remaining 58 patients, 39 had significant CAD (at least 75% diameter stenosis of at least 1 major coronary artery) and 19 had no significant CAD. The 2 test responses were considered positive if a wall motion abnormality was detected during pacing or after exercise. Sensitivity and specificity were 82% and 95% after exercise and 90% and 84% during TAP. In patients with significant CAD but without wall motion abnormalities at rest, sensitivity was 75% during pacing and 56% after exercise. In patients with significant CAD, the wall motion score index decreased significantly with both types of stress; during pacing wall motion score index was significantly lower than after exercise. Thus, 2-D echo during TAP appears to be a feasible and reliable alternative to postexercise echo for the detection of CAD.
Comparison of the results of transesophageal electrical stimulation of the left atrium, bicycle ergometry and selective coronary angiography in diagnosing ischemic heart disease. Sidorenko BA, Savchenko AP, Liakishev AA, Kozlov SG, Klembovskii AA. Kardiologiia 1985 Nov;25(11):18-25. The clinical picture and results of bicycle ergometry and selective coronarography were compared with data obtained by esophageal electric stimulation of the left atrium in 108 patients with suspected coronary disease. It was demonstrated that esophageal left-atrial electrostimulation could be used as noninvasive load test for coronary disease. Ischemic electrocardiographic changes, induced by esophageal stimulation showed good correlation to the clinical manifestation of angina pectoris and the severity of coronary atherosclerosis. The sensitivity of esophageal stimulation in the diagnosis of hemodynamically-significant coronary atherosclerosis was 82%, its specificity was 76%, the predictive value of positive results was 82%, and the predictive value of negative results, 76%, that is, essentially the same as the respective parameters of bicycle ergometry.
Echocardiography during transesophageal atrial pacing. Its applicability and diagnostic value. Salas Nieto J, Lopez Candel J, Villegas Garcia M, Garcia Garcia J, de la Morena Valenzuela G, Pico Aracil F, Campos Peris JV, Ruiperez Abizanda JA. Hospital Universitario Virgen de la Arrixaca, Murcia. Rev Esp Cardiol 1994 May;47(5):308-15. INTRODUCTION AND OBJECTIVES. Atrial pacing has been proposed as an alternative method to the isotonic exercise, to induce ischemia, and, joined to two-dimensional echocardiography, as one of the main modalities in stress echo. In order to analyse its applicability and diagnostic value in assessing coronary artery disease this study was undertaken. PATIENTS AND METHODS. 52 patients referred to coronarography for suspicion or evaluation of ischemic disease, were submitted to this technique. RESULTS. The study was completed in 44 patients (applicability rate of 84,7%). The results obtained showed a sensitivity, specificity and diagnostic accuracy for the regional wall motion abnormalities echocardiographically detected, of 88%, 68% and 79%, respectively. When electrocardiographic changes or presence of angina during atrial pacing were added to echocardiographic data, sensitivity increased to 96%. In 41 patients in which a conventional stress test was available, sensitivity was 55% electrocardiographically, 33% clinically and 68% globally. CONCLUSIONS. It is concluded that transthoracic two-dimensional echocardiography during atrial pacing is a safe, highly sensitive method for coronary artery disease detection. The limitations of the method for its routine clinical application are also analysed.
Combination of transesophageal atrial pacing and echo-dipyridamole test in the diagnosis of coronary disease in patients with suspected angina pectoris and negative exercise test. Manfredini R, Finzi A, Bertoni T, Lamarchesina U, Nador F, Lotto A. Ospedale Maggiore IRCCS, Milano. G Ital Cardiol 1994 Nov;24(11):1379-86. BACKGROUND. Echo-dipyridamole test is an useful tool for non-invasive demonstration of inducible myocardial ischemia in patients with coronary artery disease, its sensitivity being consistently higher as compared with classic exercise stress testing. However, in patients with single vessel who often perform a normal or borderline stress test, even the sensibility of echo-dipyridamole test is comparatively reduced. METHODS. In 19 patients with clinically suspected angina (effort-related in 4, at rest in 8, mixed in 7) and normal exercise stress test, standard echo-dipyridamole test was performed. Thereafter, rapid atrial pacing, a procedure associated with a sharp increase of myocardial oxygen consumption, was performed by means of a transoesophageal catheter during the proceeding 5 min and during 4 min of repeated dipyridamole 0.56 mg/kg infusion. RESULTS. Standard echo-dipyridamole test induced ventricular wall motion abnormalities in 3 patients (one with borderline exercise stress test), whereas repeated pacing-sensitized procedure obtained wall motion abnormalities (apical, septal and lateral) in the same and in 4 additional patients. Coronary angiography demonstrated > 70% stenosis in 8/19 patients (single vessel disease in 5), 7 of whom had been correctly recognized by pacing-dipyridamole test; therefore, sensitivity of the latter as compared with standard dipyridamole test was 87% and 37% respectively. The anatomic correlation of induced wall motion abnormalities with coronary arterial stenosis was demonstrated in all cases. Specificity was 100% with both methods. CONCLUSIONS. Although limited by its restricted patient population, this study suggests that atrial pacing, performed via transoesophageal catheter, can significantly improve the positive predictive value of echo-dipyridamole test in coronary artery disease. By means of this simple procedure, the possibility of non invasively diagnosing even single vessel stenosis in patients with inconclusive exercise stress testing can be significantly improved.
Detection of coronary artery disease by digital stress echocardiography: comparison of exercise, transesophageal atrial pacing and dipyridamole echocardiography. Marangelli V, Iliceto S, Piccinni G, De Martino G, Sorgente L, Rizzon P. Institute of Cardiology, University of Bari, Italy. J Am Coll Cardiol 1994 Jul;24(1):117-124. OBJECTIVES. This study assessed and compared the diagnostic potential of exercise, transesophageal atrial pacing and dipyridamole stress echocardiography in a clinical setting. BACKGROUND. Although they have been widely studied, no data exist with regard to comparisons of these procedures in a head-to-head study in different clinical settings. METHODS. One hundred four consecutive patients with suspected coronary artery disease undergoing coronary angiography and with no previous myocardial infarction or rest left ventricular wall motion abnormalities underwent digital posttreadmill, transesophageal atrial pacing and dipyridamole echocardiography. RESULTS. Feasibility of digital exercise echocardiography was 84%; 8 of 88 remaining patients had a nondiagnostic exercise echocardiographic test (inadequate exercise or imaging). In 80 patients with feasible and diagnostic digital exercise echocardiography, sensitivity, specificity and accuracy were, respectively, 89%, 91% and 90%. Eighty of the 104 patients underwent transesophageal atrial pacing and dipyridamole echocardiography. Feasibility of the alternative stress procedures was 77% for transesophageal atrial pacing and 96% for dipyridamole. In 60 patients successfully undergoing both alternative stress procedures, sensitivity and specificity were 83% and 76% for atrial pacing and 43% and 92% for dipyridamole echocardiography, respectively. In the group of 24 patients with nondiagnostic exercise echocardiography and consequent indication to alternative stress procedures, accuracy of transesophageal atrial pacing was higher than that of dipyridamole echocardiography (73% vs. 45%, p = 0.06). CONCLUSIONS. Because of its higher diagnostic potential and additional functional information, exercise is the stress of choice when stress echocardiography is used to detect the presence of coronary artery disease. Alternative stresses can be used in patients with nondiagnostic exercise echocardiography. Transesophageal and dipyridamole echocardiography differ in feasibility and diagnostic reliability (higher sensitivity of transesophageal atrial pacing, higher specificity of dipyridamole). These characteristics must be considered when selecting procedures to be used as alternatives to exercise.
From page 120 of article: "Side effects. After transesophageal atrial pacing, in no case was it necessary to administer drugs to obtain remission of the signs of ischemia induced by the test because they regressed a few seconds after stimulation. However, after dipyridamole echocardiography it was invariably necessary to administer aminophylline to stop cephalea or flushing, or both, induced by the drug. In 5 cases, it was also necessary to administer sublingual nitroglycerin and, in 2 cases, intravenous nitrates to stop agngina, ST depression or severe wall abnormalities induced by dipyridamole, which tended to persist for several minutes."
Comparison of the diagnostic potential of four echocardiographic stress tests shortly after acute myocardial infarction: submaximal exercise, transesophageal atrial pacing, dipyridamole, and dobutamine-atropine. Schroder K, Voller H, Dingerkus H, Munzberg H, Dissmann R, Linderer T, Schultheiss HP. Free University of Berlin, Germany. Am J Cardiol 1996 May 1;77(11):909-14. This study assessed and compared the diagnostic potential of submaximal exercise, transesophageal atrial pacing, dipyridamole, and dobutamine-atropine stress echocardiography tests shortly after acute myocardial infarction. In 121 study patients, 325 digital echocardiographic stress tests were attempted 10 to 11 days after acute myocardial infarction: 83 submaximal exercise tests, 121 high-dose dipyridamole echocardiography tests (DET), 69 transesophageal atrial pacing tests (< 150 beats/min), and 52 dobutamine tests, starting at 10 microgram/kg per minute, increasing stepwise to 40 microgram kg/min, and coadministering atropine in 12 patients (dobutamine-atropine stress echocardiography [DASE]). Results were correlated to a coronary artery diameter stenosis > or = 50% as determined by quantitative angiography. Feasibility to perform submaximal exercise echocardiography, atrial pacing echocardiography, DET, and DASE was 89%, 52%, 98%, and 88%, respectively. Atrial pacing was not tolerated by 18 patients and refused by 6 (9%). Severe but not life-threatening side effects were hypotension in DET (2%) and tachyarrhythmias in DASE (6%). Test positivity in multivessel disease with submaximal exercise, DET, and DASE was 55%, 93%, and 90%, respectively, and in 1-vessel disease 47%, 65%, 71%, and for atrial pacing, 82%, respectively. We conclude that submaximal exercise has limited sensitivity and atrial pacing limited feasibility. The pharmacologic stressors provide a useful, safe diagnostic approach: DET with slightly lower sensitivity in 1-vessel disease and DASE with insignificantly less feasibility.
Accuracy of Dobutamine Technetium 99m Sestamibi SPECT Imaging for the Diagnosis of Single-Vessel Coronary Artery Disease: Comparison with Echocardiography. Elhendy A, van Domburg, R, Bax J, Poldermans D, Sozzi F, Roelandt, J. Thoraxcenter and the Department of Nuclear Medicine, University Hospital, Rotterdam, The Netherlands. Am Heart J 139(2):224-230, 2000. Background: Recent experimental studies have shown that technetium 99m methoxyisobutyl isonitrile (MIBI) underestimates flow heterogeneity induced by dobutamine and that this might have an impact on the sensitivity of dobutamine MIBI in patients with single-vessel coronary artery disease (CAD). This study compares the accuracy of dobutamine MIBI single-photon emission computed tomography (SPECT) and simultaneous echocardiography in the diagnosis of single-vessel CAD. Methods and Results: Ninety-one patients (age 57 ± 12 years) with single-vessel CAD or without significant CAD were studied with dobutamine (up to 40 ?g/kg per minute)-atropine (up to 1 mg) stress echocardiography (DSE) and simultaneous MIBI SPECT imaging. CAD was predicted on the basis of myocardial ischemia (transient wall motion abnormalities by DSE and reversible perfusion defects by MIBI). Ischemia was detected by MIBI in 30 of the 54 patients with and in 10 of the 37 patients without significant single-vessel CAD (sensitivity 56%, confidence interval [CI] 45 to 66; specificity 73%, CI 64 to 82; accuracy 63%, CI 53 to 73). Ischemia was detected by DSE in 30 patients with and in 6 patients without significant CAD (sensitivity of DSE 56%, CI 45 to 66; specificity 84%, CI 76 to 91; accuracy 67%, CI 57 to 77, P = not significant vs MIBI). For both imaging methods, sensitivity was significantly higher in patients with left anterior descending than in patients with left circumflex or right coronary artery stenosis (75% vs 40%, P < .05). The addition of echocardiography to MIBI did not improve the diagnostic accuracy (68% CI 59 to 78, P = not significant vs DSE or MIBI alone). Conclusions: DSE and MIBI SPECT imaging have similar moderate sensitivity for the diagnosis of single-vessel CAD. Sensitivity of each of these techniques is higher in patients with left anterior descending than in patients with left circumflex or right coronary artery stenosis. There is no improvement of diagnostic accuracy by use of the combination of both techniques.
Value of exertional echocardiography and performance of transesophageal left atrial pacing done 3-4 weeks after acute myocardial infarction. Poprawski K, Jankowski J, Plesinski K, Smukowski T, Straburzynska-Migaj E, Stanek K, Paradowski S. I Kliniki Kardiologii Instytutu Kardiologii.Pol Arch Med Wewn 1991 Mar;85(3):160-6. Two-dimensional echocardiography during exercise (ECHO W) and left atrial pacing (ECHO S) was done in 30 patients 3-4 weeks after acute myocardial infarction. Sensitivity of these methods to detect fresh myocardial ischemia was compared. Their prognostic value during 2 years after myocardial infarction was determined too. Both methods increase sensitivity of simultaneously performed ecg. Sensitivity of ECHO S (80%) was higher than ECHO W (67%). Sensitivity of the two methods altogether was higher (93%) then each method independently. Coexistence of worsening systolic wall motion abnormalities and a decrease in ejection fraction during both examinations may suggest worse clinical course and prognosis 2 years after myocardial infarction.
Simultaneous transesophageal atrial pacing and transesophageal echocardiography in cardiac surgical patients. Hesselvik JF, Ortega RA. Boston University Medical Center. J Cardiothorac Vasc Anesth 1998 Jun;12(3):281-3. OBJECTIVES: To measure the effect of inserting a transesophageal echocardiography (TEE) probe on the pacing threshold of a previously inserted transesophageal pacing stethoscope, and to examine whether an indwelling pacing stethoscope influences the feasibility and image quality of a TEE examination. DESIGN: Prospective, open study using each patient as his/her own control. SETTING: Cardiac operating room of an academic medical center. PARTICIPANTS: Twenty adult patients in sinus rhythm and anesthetized for cardiac surgery. INTERVENTIONS: After induction of anesthesia and endotracheal intubation, a pacing stethoscope was inserted into the esophagus. A 5-MHz TEE probe was inserted to the four-chamber-view position. A full echocardiographic examination was performed, noting image quality, ease of probe manipulation, and loss of pacing. The pacing stethoscope was removed, and image quality assessed again. MEASUREMENTS AND MAIN RESULTS: The initial mean pacing threshold +/- 1 standard deviation (SD) was 19 +/- 8 mA (range, 10 to 37 mA). After placement of the echocardiography probe, the mean threshold had increased to 24 +/- 8 mA (range, 11 to 40 mA; p < 0.01). Loss of pacing with probe manipulation was noted in 15 of 20 patients (transient in 10 patients, permanent in 5 patients). Problems manipulating the probe because of sticking to the pacing stethoscope were noted in 10 of 20 patients. Poor image quality, resolving after stethoscope removal, was seen in two patients. CONCLUSION: Placement of a TEE probe results in a modest increase of the transesophageal pacing threshold. An indwelling pacing stethoscope frequently interferes with the ability to perform a full echocardiographic examination, and probe manipulation commonly causes loss of pacing.
Altered left ventricular diastolic function post-atrial pacing in coronary artery disease and left ventricular hypertrophy: further insights by pulmonary venous flow analysis. Hoffmann R, Lambertz H, Thoennissen G, Flachskampf FA, Hanrath P. Medical Clinic I, Klinikum RWTH Aachen, Germany. Eur Heart J 1994 Aug;15(8):1096-105. Left ventricular filling dynamics during acute pacing-induced myocardial ischaemia were assessed using transoesophageal atrial pacing and simultaneous Doppler measurements of pulmonary venous and mitral flow. All patients (10 with CAD and 12 with left ventricular hypertrophy due to hypertrophic cardiomyopathy; HCM) were in sinus rhythm and patients with mitral insufficiency were excluded. Data were compared with those of a control group (n = 10). Measurements were obtained at baseline (heart rate 84 +/- 14 beats.min-1) and immediately after atrial pacing via the same transoesophageal echocardiography (TEE) probe after stepwise increase of the pacing rate to 133 +/- 12 beats.min-1. Heart rate immediately after pacing was 83 +/- 13 beats.min-1. Time velocity integrals (TVI) were calculated at baseline and after pacing for the following flows: early (E) and late (A) mitral flows, as well as antegrade systolic (S), diastolic (D) and retrograde diastolic (R) pulmonary venous flows. In the control group none of the flow parameters changed significantly after pacing compared with baseline data. In contrast, in CAD patients, the TVI of the E wave, the TVI E/A ratio as well as the pulmonary venous flow changed significantly after pacing (7.3 to 5.5 cm, P < 0.05, 1.7 to 1.1, P < 0.01 and 1.0 to 2.1 cm, P < 0.001, respectively). HCM patients also showed significant changes: TVI E/A ratio post-pacing decreased from 1.9 to 1.4 (P < 0.05), and the pulmonary venous reverse flow integral increased from 1.3 to 2.8 cm (P < 0.0001). Analysis of variance showed the TVI E/A ratio to be significantly dependent on pacing (P = 0.012). The pulmonary venous retrograde flow was found to be influenced by the presence of disease (P = 0.033 before and P = 0.0001 after pacing) and in all cases by pacing (before vs after pacing P = 0.0001). Pacing resulted in significantly different changes in the TVI E/A ratio and the TVI of the retrograde pulmonary venous flow for CAD and HCM patients compared with those of control subjects. In patients with CAD and HCM, rapid atrial pacing results in a decreased early to late ventricular filling ratio because of impaired relaxation, despite presumably increased filling pressure. Retrograde pulmonary venous flow increased because of increased filling pressure and operating left ventricular stiffness.
Diagnosis of coronary disease using multiplane transesophageal echocardiography and atrial pacing . Memmola CD, Napoli VF, Oliva S, Colonna P, Massari E, Brigiani MS, Iliceto S, Rizzon P. Istituto di Cardiologia, Universita degli Studi, Bari. Cardiologia 42(3):293-8, 1997. The diagnostic value of echo-pacing has been previously report. Recently, monoplanar transesophageal echocardiography (TEE) has been used to improve the reliability of this stress procedure. Therefore, in 40 consecutive patients undergoing coronary angiography for suspected coronary artery disease (CAD) we tested the accuracy of atrial pacing (TAP) during multiplane TEE as a stress procedure. TAP was performed during TEE using a circular, adhesive electrode installed at the tip of the echoscope and connected to the pulse generator. In all patients TAP was firstly attempted by positioning the TEE probe in the esophagus and, if not successful, in the stomach. Left ventricular wall motion was monitored by means of 4, 2 chamber and long axis views from the esophagus and short axis scan from the stomach, in baseline conditions, at peak pacing and immediately after maximal heart rate. The test was considered positive if wall motion abnormalities developed during TAP. Stable capture of the atrium was obtained in 28 patients from the esophagus and in 6 patients from the stomach. Thus, TEE-TAP was performed in 34/40 patients (feasibility 85%). Wall motion abnormalities were detected during TAP in 20/24 with and in 2/10 patients without CAD. Thus, sensitivity and specificity of TEE-TAP were 83% and 80% respectively. The sensitivity of the test in single and multivessel disease resulted 72% and 92%. The 12 lead electrocardiogram during TAP showed a sensitivity of 66% and a specificity of 40% (p < 0.01 vs TEE-TAP). In conclusion, TEE-TAP is a new approach for CAD evaluation providing a complete and accurate imaging of left ventricular wall motion.
Feasibility and safety of transesophageal stress echocardiography. Zabalgoitia M, Gandhi DK, Abi-Mansour P, Rosenblum J. University of Texas Health Science Center. Am J Med Sci 1992 Feb;303(2):90-4. To determine the feasibility and safety of transesophageal stress echocardiography (TSE), 86 patients with chest pain syndrome were studied. The TSE test consists of transesophageal atrial pacing during simultaneous monitoring of left ventricular contractility by the use of transesophageal echocardiography. An octapolar pacing catheter attached to the transesophageal echoscope was used in conjunction with a cardiac stimulator to induce pacing-tachycardia. The optimal pair of electrodes was chosen from 13 possible combinations of the 8-electrode catheter. The pacing rate was increased until greater than or equal to 90% maximal age-predicted heart rate was reached or significant wall motion abnormalities were developed. The test was also stopped if ischemic electrocardiographic changes or progressive chest pain occurred. A successful TSE test was performed on 77 patients (90%). Twenty-one patients (24%) developed Wenckebach AV block during pacing that was resolved by intravenous atropine sulfate in all but one of them. The TSE test could not be completed in nine patients (10%) because we were unable to capture in four patients (5%), there were suboptimal images in three patients (3%), and two patients suffered intolerable epigastric discomfort (2%). Pacing-induced wall motion abnormalities were identified in 53 patients (69%). No serious complications were noted. We conclude that TSE is a feasible nonexercise stress test that can be performed safely in patients with suspected coronary artery disease.
Transesophageal stress echocardiography: detection of coronary artery disease in patients with normal resting left ventricular contractility. Zabalgoitia M, Gandhi DK, Abi-Mansour P, Yarnold PR, Moushmoush B, Rosenblum J. University of Texas Health Science Center, San Antonio. Am Heart J 1991 Nov;122(5):1456-63 A new nonexercise test to detect significant coronary disease was prospectively evaluated in 36 patients with chest pain syndrome and normal left ventricular contractility. Transesophageal atrial pacing was used to provoke ischemia during monitoring of left ventricular contractility by transesophageal echocardiography. A 12-lead ECG was recorded. A TSE was abnormal if new segmental wall motion abnormalities developed. On the basis of the TSE results, patients were separated into normal (group 1, n = 16) and abnormal response (group 2, n = 20). Arteriography revealed significant disease in 21 patients, 19 from group 2 and two from group 1. Sensitivity and specificity of TSE were 90% and 93%, respectively, and those for pacing ECG were 43% and 100%, respectively. In addition, TSE accurately predicted the coronary artery perfusion bed involved. In 10 patients, Wenckebach AV block developed during pacing and resolved immediately by the administration of atropine sulfate. No serious complications were seen. Thus TSE is a highly sensitive and specific novel technique to detect significant coronary disease in patients with chest pain syndrome and normal resting left ventricular contractility.
Biplane transesophageal pacing echocardiography compared with dipyridamole thallium-201 single-photon emission computed tomography in detecting coronary artery disease. Norris LP, Stewart RE, Jain A, Hibner CS, Chaudhuri TK, Zabalgoitia M. University of TX Health Sci Ctr at San Antonio. Am Heart J 1993;126(3 Pt 1):676-85 TPE is a new diagnostic technique that uses simultaneous graded transesophageal left atrial pacing and biplane transesophageal echocardiography for the detection of pacing-induced wall motion abnormalities. In a prospective study 30 patients underwent biplane TPE, dipyridamole thallium-201 single-photon emission computed tomography (SPECT), and coronary arteriography. The sensitivity (86% vs 95%, p = not significant [NS]), specificity (89% vs 56%, p = NS), positive predictive value (95% vs 73%, p = NS), and negative predictive value (83% vs 83%, p = NS) of biplane TPE and thallium-201 SPECT in identifying patients with significant coronary artery disease was similar. In the 90 vascular territories analyzed, the agreement between biplane TPE and thallium-201 SPECT for presence or absence of significant disease was 71%. Analysis of the three major vascular territories demonstrated that each imaging modality had a high sensitivity and specificity in the left anterior descending and right coronary artery segments. However, the two techniques demonstrated poorly sensitivity in the segmental distribution of the circumflex coronary artery. In conclusion, biplane TPE compared favorably with thallium-201 SPECT in terms of safety and accuracy for detecting significant coronary artery disease. Accordingly, biplane TPE may be a suitable alternative for those patients with nondiagnostic thallium-201 SPECT studies and in those with contraindications to adenosine or dipyridamole.
Effect of heart rate on left ventricular diastolic transmitral flow velocity patterns assessed by Doppler echocardiography in normal subjects. Harrison MR, Clifton GD, Pennell AT, DeMaria AN. University of Kentucky, Lexington. Am J Cardiol 1991 Mar 15;67(7):622-7. Although a number of factors, including age and ventricular loading, are known to influence the pattern of left ventricular (LV) filling as depicted by Doppler echocardiographic transmitral flow velocities, few and conflicting data are available regarding the influence of heart rate (HR). Therefore, 20 volunteers (mean age 30 years) were evaluated with pulsed-wave Doppler echocardiography, performed with the sample volume placed at the mitral anulus level in the apical 4-chamber projection. Transmitral flow measurements comprised peak and integrated early passive (E) and late atrial (A) filling velocities and the slope of velocity decline from peak E filling. Measurements were recorded during baseline (sinus rhythm, mean 70 beats/mi) and during transesophageal atrial pacing (mean 88 beats/min). LV end-diastolic dimension, mean arterial pressure and PR interval (corrected for pacing-induced delay in interatrial conduction time) were unchanged during pacing versus baseline measurements. Peak and integrated E filling velocities averaged 0.59 +/- 0.09 m/s and 6 +/- 1 cm, respectively, at baseline and were not significantly greater at the higher HR. In contrast, baseline peak and integrated A velocities averaged 0.37 +/- 0.06 m/s and 2.3 +/- 0.7 cm, respectively, but were significantly greater at the higher HR (0.5 +/- 0.07 m/s and 3.2 +/- 1.1 cm, respectively [p < 0.003 vs baseline for each]). Further analysis of a subgroup of 9 subjects for whom Doppler measurements were available at 3 HRs (sinus 70; pacing 80 and 90) yielded strong evidence for a linear relation between HR and peak A velocity (A = 0.008 HR - 0.21, with p < 0.0001 for significance of the linear trend).
Influence of beta-adrenergic blockade upon hemodynamic response to exercise assessed by Doppler echocardiography. Clifton GD, Harrison MR, DeMaria AN. Clinical Practice Division, College of Pharmacy, University of Kentucky, Lexington. Am Heart J 1990 Sep;120(3):579-85. Peak aortic blood flow acceleration and velocity measured by Doppler echocardiography have been documented to be accurate descriptors of left ventricular systolic function. Both acceleration and velocity are reduced in the presence of beta-blockade at rest and during exercise. Whether and to what extent the simultaneous alterations in heart rate (HR) due to beta-blockade affect these parameters has received little study. In order to determine the influence of alterations in HR on Doppler measurements of velocity and acceleration, 10 healthy men were studied during upright exercise under control conditions, following propranolol administration, and following propranolol plus transesophageal atrial pacing. In addition, we assessed the response of stroke volume (measured as flow velocity integral) during beta-blocked and control exercise. Propranolol significantly reduced acceleration and velocity during all stages of exercise compared with control values (p < 0.05). Increasing the HR during exercise via pacing had no effect on acceleration or velocity compared with propranolol administration alone, thus demonstrating that during upright exercise, changes in acceleration and velocity are independent of alterations in HR. At low levels of exercise, propranolol significantly reduced flow velocity integral (FVI) compared with control (-1.14 cm, p < 0.05.). At high levels of exertion, however, FVI exceeded values obtained during control conditions (1.2 cm at stage 4). Pacing during beta-blockade reduced FVI at high levels of exercise but had no effect at lower levels. Our results suggest that during low levels of exercise stroke volume is increased as a consequence of both increased contractility and augmented left ventricular filling.
Effects of heart rate increase by transesophageal stimulation on the left ventricular filling in the normal subject. A pulsed echo-Doppler study. Roul G, Bareiss P, Facello A, Burggraf C, Rochoux G, Kraenner C, Mossard JM, Sacrez A. Service de cardiologie, hopital de Hautepierre, CHRU de Strasbourg. Arch Mal Coeur Vaiss 1991 Feb;84(2):189-94. The effects of increasing the heart rate on left ventricular filling were studied by Doppler echocardiography in 12 mildly sedated normal subjects. The heart rate was increased by 10, 20 and 30 bpm with respect to the basal rhythm by transoesophageal pacing. Four stages were thereby defined: S0, S1, S2 and S3. The principal results were: absence of variation of the isovolumic relaxation period in absolute values (92 +/- 14, 86 +/- 16, 87 +/- 16, 78 +/- 11 ms); absence of variation of the duration of the rapid filling period (246 +/- 36 at 50 vs 220 +/- 28 ms at 53); no change in peak filling velocity (72 +/- 11 at 50 vs 61 +/- 11 ms at 53) or in the timing of peak velocity (77 +/- 12 at 50 vs 72 +/- 13 ms at 53); increased contribution of atrial systole during tachycardia (Vmax 43 +/- 7 at 50 vs 76 +/- 17 cm/s at 53). Therefore, of these Doppler echo parameters, only atrial systole changed during the range of tachycardia rates which were studied. Its increase compensated the loss of diastolic diastasis. These changes should be born in mind in Doppler echocardiographic studies of left ventricular diastolic function.
Outcome of Doppler parameters of left ventricular systolic function during atrial stimulation as a function of coronary disease. Selton-Suty C, Anconina J, Buffet P, Grentzinger A, Julliere Y, Brembilla-Perrot B, Danchin N, Cherrier F. CHU Nancy-Brabois. Arch Mal Coeur Vaiss 1993 Nov;86(11):1551-6. The authors studied the effects of transoesophageal atrial pacing on Doppler parameters derived from flow in the left ventricular out flow tract (maximal velocity (V max), velocity-time integral (VTI), mean acceleration of aortic flow (Acc), acceleration force (AF) of the left ventricle). These parameters were recorded in patients with normal left ventricular wall motion at rest, with and without coronary disease. Eight patients had angiographically normal coronary arteries (Group 1) and 21 had coronary disease (Group 2) including 10 with an isolated stenosis of the left anterior descending artery (Group 2a) and 11 with multivessel disease (Group 2b). The heart rate was increased by increments of 20 beats per minute from 90 to 130 each minute. In coronary patients, atrial pacing resulted in a fall in V max from 0.99 +/- 0.15 to 0.90 +/- 0.12 m/s, p < 0.0005 and in AF from 23.1 +/- 6.3 to 19.6 +/- 4.8 Kdynes, p < 0.0005, whereas the Acc remained stable (13.51 +/- 3.27 and 13.53 +/- 2.47 m/s/s, NS). Conversely, V max (1.04 +/- 0.11 and 1.04 +/- 0.11, NS) and AF (25.2 +/- 5.7 and 26.3 +/- 6.7, NS) were unchanged in normal controls and the Acc improved from 13.87 +/- 3.61 to 17.04 +/- 3.49, (p < 0.05). The VTI fell significantly in both groups. The percentage variations of V max, Acc and AF were significantly different in coronary patients compared with normal controls. There were no differences between the two coronary subgroups.
Effects of atrial pacing stress test on ultrasonic integrated backscatter cyclic variations in normal subjects and in patients with coronary artery disease. Iliceto S, Galiuto L, Colonna P, Napoli VF, Rizzon P. Institute of Cardiology, University of Bari, Italy.Eur Heart J 1997 Oct;18(10):1590-8. AIMS: To evaluate the effects of acute, atrial pacing-induced, reversible myocardial ischaemia on myocardial thickening and integrated backscatter cyclic variations in patients with or without coronary artery disease. METHODS AND RESULTS: Thirty-six patients with suspected coronary artery disease underwent transoesophageal echocardiography with simultaneous atrial pacing, and coronary angiography. In myocardial segments not related to a significantly narrowed coronary artery, both from patients with and without coronary artery disease, thickening and integrated backscatter cyclic variations were not reduced at peak pacing. In segments related to a significantly narrowed coronary artery, thickening decreased at peak pacing, was still reduced at pacing interruption and recovered at 2 min, while backscatter cyclic variations, blunted at peak pacing, immediately recovered after pacing interruption. CONCLUSION: During stress-induced myocardial ischaemia, backscatter cyclic variations are blunted and thickening reduced. Returning to baseline, pre-atrial pacing values occur more rapidly in backscatter cyclic variations than when thickening takes place. Evaluation of stress-induced alterations in backscatter cyclic variations may aid in the identification of ischaemia-induced regional left ventricular functional impairment and, hence, incoronary artery disease diagnosis.
Diagnosis of coronary disease using multiplane transesophageal echocardiography and atrial pacing. Memmola CD, Napoli VF, Oliva S, Colonna P, Massari E, Brigiani MS, Iliceto S, Rizzon P. Istituto di Cardiologia, Universita degli Studi, Bari. Cardiologia 1997 Mar;42(3):293-8. The diagnostic value of echo-pacing has been previously report. Recently, monoplanar transesophageal echocardiography (TEE) has been used to improve the reliability of this stress procedure. Therefore, in 40 consecutive patients undergoing coronary angiography for suspected coronary artery disease (CAD) we tested the accuracy of atrial pacing (TAP) during multiplane TEE as a stress procedure. TAP was performed during TEE using a circular, adhesive electrode installed at the tip of the echoscope and connected to the pulse generator. In all patients TAP was firstly attempted by positioning the TEE probe in the esophagus and, if not successful, in the stomach. Left ventricular wall motion was monitored by means of 4, 2 chamber and long axis views from the esophagus and short axis scan from the stomach, in baseline conditions, at peak pacing and immediately after maximal heart rate. The test was considered positive if wall motion abnormalities developed during TAP. Stable capture of the atrium was obtained in 28 patients from the esophagus and in 6 patients from the stomach. Thus, TEE-TAP was performed in 34/40 patients (feasibility 85%). Wall motion abnormalities were detected during TAP in 20/24 with and in 2/10 patients without CAD. Thus, sensitivity and specificity of TEE-TAP were 83% and 80% respectively. The sensitivity of the test in single and multivessel disease resulted 72% and 92%. The 12 lead electrocardiogram during TAP showed a sensitivity of 66% and a specificity of 40% (p < 0.01 vs TEE-TAP). In conclusion, TEE-TAP is a new approach for CAD evaluation providing a complete and accurate imaging of left ventricular wall motion.
Use of Doppler echocardiography for studying hemodynamics in paroxysmal supraventricular tachycardia. Osipov MA, Bashchinskii SE. Kardiologiia 1991 Mar;31(3):51-4. Eighteen patients in whom sustained supraventricular tachycardia paroxysms were induced by programmed transesophageal pacing were examined. Doppler echocardiography was used to study left ventricular systolic and diastolic function, as well as cardiac output and pulmonary systolic pressure during sinus rhythm and paroxysms. A profound decrease in the cardiac index during paroxysms was found in 2 patients, one of them had higher pulmonary pressure. The cardiac index increased on an average from 4.4 +/- 0.9 l/min.m-2 during sinus rhythm to 4.8 +/- 1.4 l/min.m-2 during paroxysms. The diastolic function of the left ventricle was ascertained to be one of he factors that determine cardiac index in supraventricular tachycardia paroxysms.
Diagnostic value of left ventricular diastolic function using pulsed Doppler echocardiography in patients with ischemic heart disease. Bashchinskii CE, Osipov MA. Kardiologiia 1991 Sep;31(9):28-31. Transesophageal atrial pacing was performed in 54 patients (mean age 50.0 +/- 6.8 years) to diagnose coronary heart disease (CHD). ECG was recorded in 12 leads during the test. Echocardiography was used to assess local contractile disorders. The diastolic function of the left ventricle was examined by pulsed Doppler echocardiography in the postpacing period. Thirty eight patients were found to have altered Doppler parameters for transmitral blood flow in the postpacing period as compared to the resting period. Sixteen patients without CHD displayed no changes in the left ventricular diastolic function in the postpacing period. Two types of transmitral blood flow disorders were identified in CHD patients in the postpacing period. The so-called "pseudonormal" type of transmitral blood flow was typical of patients with the most severe contractile impairments and grave course. Abnormalities in local contractility and signs of left ventricular diastolic dysfunction were ascertained to be a sensitive marker for myocardial ischemia.
Prognostic significance of post-infarction "silent" ischemia. Chikavashvili DI, Blokhin AB, Rado Iu, Iliasov AA, Ruda MI. Kardiologiia 1991 Jun;31(6):47-50. To study the predictive value of silent ischemia, a total of 132 patients with first transmural myocardial infarction were examined, 69 had anterior and 63 had inferior myocardial infarction. On days 8-12 of onset of the disease, all the patients underwent loading two-dimensional echocardiography along with transesophageal pacing, as well as polyposition coronary angiography. According to the echocardiographic findings, 3 groups of patients were identified: 1) 34 (25.8%) with painful ischemia; 2) 37 (28.0%) with silent ischemia; 3) 61 (46.2%) with a negative test. Ischemic alterations were more frequently seen in inferior (73%) than in anterior (36.2%) myocardial infarction. The patients with painful ischemia showed a lower threshold of ischemia occurrence, more severe and prolonged ST segment depression, and greater extent of an asynergic area than did the patients with silent ischemia. A 1-5-year (mean 2.4) follow-up revealed that in terms of the risk for postinfarction angina, recurrent myocardial infarction and fatal outcomes, patients with silent ischemia represent an intermediate group between those with painful ischemia and those who have a negative load test.
Simultaneous transesophageal atrial pacing and transesophageal two-dimensional echocardiography: A new method of stress echocardiography. Lambertz H, Kreis A, Trumper H, Hanrath P. Clin Investig (Germany), 1994, 72(3):206-8. The diagnostic use of exercise echocardiography has been widely reported. However, transthoracic exercise echocardiography is inadequate in up to 20% of patients because of poor image quality related to exercise. In an attempt to overcome these limitations, a system was developed in which transesophageal echocardiography is combined with simultaneous transesophageal atrial pacing by means of the same probe. In a prospective study, transesophageal echocardiography was performed before, during and immediately afler maximal atrial pacing in 50 patients with suspected coronary artery disease. Results of transesophageal stress echocardiography were considered abnormal when new pacing-induced regional wall motion abnormalities were observed. Correlative routine bicycle exercise testing was carried out in 44 patients. Cardiac catheterization was performed in all patients. The success rate in obtaining high quality diagnostic images was 100% by transesophageal echocardiography. All nine patients without angiographic evidence of coronary artery disease had a normal result on the transesophageal stress echocardiogram (100% specificity). 38 of 41 patients with coronary artery disease (defined as 50% luminal diameter narrowing of at least one major vessel) had an abnormal result on the transesophageal stress echocardiogram (93% sensitivity). The sensitivity of the technique for one, two or three vessel disease was 85%, 100% and 100%, respectively, compared with 44%, 50% and 83%, respectively, for bicycle exercise testing; the 12 lead electrocardiogram (ECG) during rapid atrial pacing showed a sensitivity of 25%, 64% and 86%, respectively. Thus, rapid atrial pacing combined with simultaneous transesophageal echocardiography is a highly specific and sensitive technique for the detection of coronary artery disease. Ischemia-induced wall motion abnormalities were detected earlier than observed ECG changes. The technique appears to be particularly suited to patients who are unable to perform an active stress test or those with poor quality transthoracic echocardiograms.
Usefulness of combined two-dimensional echocardiography and transesophageal atrial stimulation early after acute myocardial infarction. Res JC, Kamp O, Delemarre BJ, Visser CA. Free University Hospital, Amsterdam. Am J Cardiol 1995 76(16):1112-4. Transesophageal atrial stimulation (TRAS) was combined with 2-dimensional echocardiography in 69 consecutive patients on days 3 to 5 (mean 3.3) of their first, uncomplicated myocardial infarction, to determine if inducible remote asynergy (i.e., not directly adjacent to the infarcted area and supposedly related to another vascular territory) provides information regarding (1) extent of coronary artery disease, and (2) future ischemic events. Uncomplicated, adequate stress studies were performed in 59 of 69 patients (86%); all these patients had regional asynergy at rest. Remote asynergy at rest was present in 7 patients and during TRAS in 26 patients. Coronary angiography was performed within 2 to 3 weeks after the acute phase. Multivessel disease was present in 23 of these patients and absent in 3. Of the 33 patients without remote asynergy during TRAS, 5 had multivessel disease. Sensitivity of remote asynergy during TRAS for detecting multivessel CAD was 82%, specificity 90%, and predictive accuracy 86%. New ischemic events, defined as recurrent infarction, cardiac death, or revascularization within 12 to 18 months (mean 12.6) occurred in 24 patients (41%); remote asynergy during TRAS was present in 16 of these patients (67%). It is concluded that TRAS combined with 2-dimensional echocardiography can safely be performed in the early days of acute myocardial infarction; remote asynergy during TRAS reliably identifies patients with multivessel disease and future ischemic events.
Usefulness of esophageal pill electrode atrial pacing with quantitative two-dimensional echocardiography for diagnosing coronary artery disease. Matthews RV; Haskell RJ; Ginzton LE; Laks MM. Heart Institute, Los Angeles. Am J Cardiol, 1989, 64(12) p730-5.Noninvasive diagnosis of coronary artery disease (CAD) is difficult in patients who are unable to exercise. In this study esophageal pill electrode atrial pacing was used as a myocardial stress not requiring exercise, and changes in ejection fraction and pressure volume ratio during pacing with 2-dimensional echocardiography were quantitatively analyzed. All patients had completed a Bruce protocol treadmill exercise test and had undergone coronary arteriography. Of 26 patients, 22 were successfully paced (85%). Comparable rate-pressure products were obtained for treadmill exercise (23,500 +/- 5,900 mm Hg/min) and pacing (24,100 +/- 4,400 mm Hg/min; difference not significant). Of the 22 patients completing the study 8 had normal coronary arteries (group I) and 14 had CAD (group II). The change in ejection fraction with pacing in group I patients was not significant (3 +/- 8%). In group II ejection fraction decreased with pacing (-8 +/- 13%; p = 0.025). The pressure/volume ratio increased in group I with pacing (3.8 +/- 1.8 mm Hg/min/m2; p = 0.05) and was unchanged in group II (0.3 +/- 1.8 mm Hg/min/m2; difference not significant). Using an ejection fraction decrease with pacing or a failure to increase pressure/volume ratio with pacing as criterion for the presence of CAD, similar predictive accuracies were obtained when compared to treadmill exercise testing. Esophageal pill electrode atrial pacing with quantitative 2-dimensional echocardiography may be a useful noninvasive, nonexercise method to detect CAD.
Simultaneous transesophageal echocardiography and atrial pacing: assessment of the functional significance of coronary artery disease before surgical treatment of an abdominal aneurysm. Stempfle HU, Kruger TM; Brandl BC, Theisen K, Angermann CE. Ludwig Maximilians Universitat Munchen. Clin Investig 1994 Feb;72(3):206-8. Conventional active stress tests for the evaluation of coronary artery disease are not feasible for patients in whom a significant blood pressure increase during a stress procedure should be avoided, for example, those with a coexisting aortic aneurysm. Transesophageal echocardiography (TEE) with simultaneous atrial pacing is a new, highly specific, and sensitive stress technique for the detection of coronary artery disease. Furthermore, TEE can be performed safely with only mild blood pressure increases. Therefore in the present case report of a 70-year-old male, application of combined TEE and atrial pacing was used successfully to exclude the hemodynamic significance of a circumflex artery stenosis and avoided a significant blood pressure increase before surgical correction of an abdominal aortic aneurysm.
Simultaneous Transesophageal Two-Dimensional Echocardiography and Atrial Pacing for Detecting Coronary Artery Disease Kamp O, De Cock C, Kupper A, Roos J, Visser C. Free University Hospl, and the Interuniversity Cardiol Inst, Amsterdam, Am J Cardiol 1992;69:1412-1416. This study describes a new technique for assessing wall motion abnormalities, combining transesophageal echocardiography (TEE) and transesophageal atrial pacing in 71 patients. Stable capture was reached in 70 patients (99%). In 3 patients (4%) pacing was discontinued prematurely because of discomfort. TEE during pacing was performed in 52 patients with and in 18 patients without coronary artery disease (CAD). In 43 of 52 patients with CAD, regional wall motion abnormalities occurred (sensitivity 83%). No wall motion abnormalities occurred in 17 of 18 patients without CAD (specificity 94% positive predictive value 98%). Wall motion abnormalities related to another vascular region were observed in 17 of patients with previous myocardial infarction (sensitivity 77% specificity 100% positive predictive value 100%). Simultaneous 12-lead electrocardiography during atrial pacing was performed in 57 patients and yielded positive results in 21 of 40 patients with (sensitivity 52%) and in 3 of 17 patients without CAD (specificity 82%, positive predictive value 88%). Exercise stress testing was performed in 66 patients. Twenty-four of 48 patients with CAD had a positive exercise electrocardiogram (sensi tivity 50?/O); a false-positive exercise electrocardio- gram was observed in 3 of 18 patients (specificity 83%, positive predictive value 89%). lt is concluded that TEE during transesophageal atrial pacing is a feasible and promising alternative technique for the assessment of CAD, with a higher sensitivity than simultaneous 12-lead and exercise electrocardiography.
High quality stress echocardiography using simultaneous transesophageal echocardiographic imaging and atrial pacing. Kamp O, DeCock CC, Visser CA. Free University Hosp, and the Interuniversity Cardiol Inst, Amsterdam. Echocardiography, Vol 12, Jan 1996. The combination of transesophageal atrial pacing and transesophageal echocardiography (TEE) provides an alternative stress echocardiographic technique capable of assessing pacing-induced wall-motion abnormalities and ischemia-induced mitral regurgitation. The rationale for combining pacing with TEE resulted from experiences with inadequate transthoracic stress studies in up to 15% of the patients and second, from failure of transesophageal atrial pacing with a single lead in another 15% of the patients. Simultaneous TEE and transesophageal atrial pacing was performed in 90 consecutive patients using continuous short-axis monitoring obtained at papillary muscle level. All but one patient had good image quality at rest and during pacing. No complications occurred, in three patients (6%) pacing had to be discontinued prematurely because of discomfort. Early atrioventricular Wenckebach block occurred in eight patients (9%). In 83 patients (92%) coronary artery angiography was performed Sensitivity for assessment of suspected coronary artery disease was 83%, and specificity 94%. Multivessel disease in patients with prior myocardial infarction was assessed with sensitivity of 77%, and specificity of 100%. In 6 of 25 patients (24%) new or increasing mitral regurgitation after induction of wall-motion abnormalities was observed. In conclusion, TEE in conjunction with atrial pacing is feasible, safe, and an alternative echocardiographic stress technique, capable of detecting wall-motion abnormalities and changes in mitral regurgitation. Because of its semi-invasive nature, only patients with a poor transthoracic window are candidates.
Usefulness of transesophageal atrial pacing combined with two-dimensional echocardiography (echo-pacing) in predicting the presence and site of residual jeopardized myocardium after uncomplicated acute myocardial infarction. Anselmi M, Golia G, Marino P, Prioli MA, Rossi A, Franceschini L, Carbonieri E, Zardini P. Am J Cardiol 1994;73(8):534-8. The usefulness of transesophageal atrial pacing combined with 2-dimensional echocardiography (echo-pacing) in predicting the presence and site of jeopardized myocardium, defined as areas of myocardium perfused by a vessel with a stenosis or = 75% or by a collateral circulation if the supplying vessel was occluded, was evaluated in 31 patients with uncomplicated acute myocardial infarction who underwent coronary angiography. All 5 patients without jeopardized myocardium had a negative test, whereas 24 of 26 with jeopardized muscle had a positive test (sensitivity 92%; specificity 100%). To identify the site of jeopardized myocardium, tests that were positive for development of new asynergies were analyzed further, distinguishing those positive in the infarct or remote zone. Seven of 8 patients with new asynergies in the remote zone had areas of jeopardized myocardium outside the territory of distribution of the infarct-related vessel, whereas only 2 of 12 with new asynergies in the infarct zone had areas of jeopardized myocardium outside that territory (p 0.01), correctly predicting the site of jeopardized myocardium in 17 of 20 cases. In conclusion, echo-pacing is useful for detecting the presence and site of jeopardized myocardium after an acute myocardial infarction.
Comparison of left ventricular function and volumes during transesophageal atrial pacing combined with two-dimensional echocardiography in patients with syndrome X, atherosclerotic coronary artery disease, and normal subjects. Anselmi M, Golia G, Marino P, Vitolo A, Rossi A, Caraffi G, Carbonieri E, Zardini P. Division of Cardiology, University of Verona, Italy. Am J Cardiol 1997 Nov 15;80(10):1261-5. Nine patients with syndrome X were compared with 2 groups of patients known to have coronary artery disease (CAD) (8 patients who developed regional wall motion abnormalities [group ECHO+] and 6 patients who showed only ST depression at echo-pacing [group ECG+]) and with 6 healthy volunteer control subjects. Left ventricular function at rest was normal in all patients. End-diastolic and end-systolic volumes (ml/m2) and ejection fraction were calculated at baseline and at peak of echo-pacing using a Simpson's biplane method. No regional wall motion abnormalities were observed during the echo-pacing in patients with syndrome X or in the volunteers. End-diastolic volume decreased in patients with syndrome X, in the volunteers (from 47 +/- 11 to 30 +/- 12 and from 72 +/- 7 to 38 +/- 6, respectively, p <0.01 for both), and in ECG+ patients (from 48 +/- 10 to 33 +/- 6, p <0.05), whereas it did not change in ECHO+ patients. End-systolic volume decreased in patients with syndrome X and in the volunteers (from 17 +/- 5 to 11 +/- 4 and from 28 +/- 6 to 16 +/- 4, respectively, p <0.01 for both), whereas it did not change or else slightly increased in patients with CAD (from 18 +/- 10 to 16 +/- 5 for ECG+ patients and from 19 +/- 5 to 24 +/- 9 for ECHO+ patients, p = NS for both), regardless of whether regional wall motion abnormalities appeared. Ejection fraction decreased in ECG+ and ECHO+ patients (from 64 +/- 12 to 52 +/- 11 and from 62 +/- 9 to 44 +/- 13, respectively, p <0.01 for both), whereas it did not change in patients with syndrome X and in the volunteers (from 64 +/- 8 to 61 +/- 8 and from 61 +/- 7 to 58 +/- 7, respectively, p = NS for both). During echo-pacing in syndrome X patients no regional wall motion was detected. Left ventricular volumes and ejection fraction showed the same patterns of variation in these patients as they did in the healthy control subjects, in contrast with those patients with CAD, whether or not regional wall motion abnormalities appeared in the latter.
Influence of pacing-induced myocardial ischemia on left atrial regurgitant jet: a transesophageal echocardiographic study. Kamp O, de Cock CC, van Eenige MJ, Visser CA. Free University Hospital, Amsterdam. J Am Coll Cardiol 1994; 23(7):1584-91. OBJECTIVES. We investigated the influence of pacing-induced myocardial ischemia on systolic regurgitant jet in the left atrium, using simultaneous transesophageal echocardiography and transesophageal atrial pacing. BACKGROUND. In vitro studies have shown that ischemia-induced mitral regurgitation may occur as a result of mitral leaflet malcoaptation or (global) left ventricular dysfunction. However, no transesophageal echocardiographic study has thus far been performed to demonstrate the mechanism and extent of mitral regurgitation during myocardial ischemia in patients. METHODS. In 24 patients (mean [+/-SD] age 57 +/- 10 years) with (15 patients) and without (9 control subjects) coronary artery disease, heart rate, blood pressure and systolic regurgitant jet were assessed before and immediately after pacing. Pacing was increased stepwise up to 160 beats/min to provoke wall motion abnormalities while the left ventricular short axis was monitored at the midpapillary muscle level. Other variables obtained before and at peak pacing included left ventricular end-diastolic and end-systolic areas and left ventricular end-diastolic and end-systolic endocardial segmental lengths. RESULTS. Heart rate and blood pressure before and after pacing were not significantly different in control subjects or in patients. At baseline, a jet was present in all but three control subjects. New or increased anterior or posterior wall motion abnormalities were observed during pacing in seven and eight patients, respectively. End-systolic left ventricular areas and segment lengths were significantly reduced in control subjects compared with patients with coronary artery disease at peak pacing (p < 0.05). The increase in systolic regurgitant jet was significantly greater in patients (2.0 +/- 1.1 to 3.1 +/- 1.8 cm2 vs. 0.7 +/- 0.7 to 0.9 +/- 0.9 cm2 [after pacing], p < 0.01). This effect was greater in patients with posterior than with anterior wall motion abnormalities (3.5 +/- 1.6 vs. 2.1 +/- 1.2 cm2 [after pacing], p < 0.05). CONCLUSIONS. Quantitative changes in geometry and function of the left ventricle caused by pacing-induced myocardial ischemia augments systolic regurgitant jet size. An increase in the jet during atrial pacing is associated with new or increased wall motion abnormalities, especially of the posterior wall. Pacing-induced anterior wall motion abnormalities appear not to be related directly to an increase in the jet.
Comparison of postexercise and transesophageal atrial pacing two-dimensional echocardiography for detection of coronary artery disease. liceto S, D'Ambrosio G, Sorino M, Papa A, Amico A, Ricci A, Rizzon P (Italy). Am J Cardiol, 1986, 57(8) p547-53 Two-dimensional (2-D) echocardiography during transesophageal atrial pacing (TAP) was recently proposed as an alternative to exercise 2-D echocardiography for the diagnosis of coronary artery disease (CAD). To compare these 2 methods, 78 consecutive patients with good-quality echocardiographic (echo) examinations at rest were studied. Two-dimensional echocardiography was performed immediately after supine bicycle exercise and at peak atrial pacing obtained with transesophageal atrial stimulation. Twenty patients were excluded: 16 because of poor quality of 2-D echo images after exercise and 4 because of inadequate TAP studies (atrial capture not achieved in 2 and intolerance in 2). Of the remaining 58 patients, 39 had significant CAD (at least 75% diameter stenosis of at least 1 major coronary artery) and 19 had no significant CAD. The 2 test responses were considered positive if a wall motion abnormality was detected during pacing or after exercise. Sensitivity and specificity were 82% and 95% after exercise and 90% and 84% during TAP. In patients with significant CAD but without wall motion abnormalities at rest, sensitivity was 75% during pacing and 56% after exercise. In patients with significant CAD, the wall motion score index decreased significantly with both types of stress; during pacing wall motion score index was significantly lower than after exercise. Thus, 2-D echo during TAP appears to be a feasible and reliable alternative to postexercise echo for the detection of CAD.
Stress echocardiography with transesophageal atrial pacing: preliminary report of a new method for detection of ischemic wall motion abnormalities. Chapman PD; Doyle TP; Troup PJ; Gross CM; Wann LS. Circulation (United States), Sep 1984, 70(3) p445-50. We performed two-dimensional echocardiography in 19 patients with significant coronary artery disease and in six normal volunteers at rest and during transesophageal atrial pacing. Technically adequate resting echocardiograms were obtained in 18 of the 19 patients and in all six normal volunteers. In two subjects, atrial capture was not possible, and in one subject, discomfort from the pacing at the beginning of the study precluded its completion. In all subjects (n = 21) who completed the protocol satisfactory two-dimensional echocardiograms were obtained during pacing. Wall motion was normal at rest and during atrial pacing in five normal volunteers. New transient wall motion abnormalities developed in 13 of the 16 patients during pacing. Twelve of the 13 patients had significant coronary lesions in the coronary arteries supplying the abnormal wall segment. Only three of the patients developed significant ST segment depression during pacing. We conclude that stress echocardiography with transesophageal atrial pacing is safe and practical and can be used in patients who cannot perform dynamic exercise, this technique can detect ischemic segmental wall motion abnormalities corresponding to the distribution of coronary arterial obstruction, and the technique provides high-quality echocardiographic images during stress and thus may expand the usefulness of resting two-dimensional echocardiography in patients who have ischemic heart disease.
Evaluation of Doppler echocardiography stress test with transesophageal atrial pacing in detecting coronary artery disease. Hua Q .Capital Institute of Medicine, Beijing Chung Hua Hsin Hsueh Kuan Ping Tsa Chih (China), Dec 1991, 19(6) p351-2, 396-7. Doppler echocardiographic transesophageal atrial pacing stress test was performed in 23 patients with coronary artery disease (CAD) and 35 normal subjects. It was found that 1/3 filling fraction (1/3 FF) decreased and peak flow velocity of atrial contraction (APFV), time velocity integral of atrial contraction (ATVI) and the ratio of ATVI to total TVI (ATVI/TTVI) increased immediately after rapid atrial pacing in CAD group. No differences were found between before and after pacing in normal group. Using 2 of the 3 criteria ATVI/TTVI greater than 0.35, ATVI increases and 1/3 FF decreases after pacing as the criteria for diagnosis in CAD, the sensitivity was 86% and specificity was 77%. Thus, Doppler echocardiographic transesophageal atrial pacing stress test may be a feasible, reliable and noninvasive method in detecting CAD.
Evaluation of the effects of gallopamil in patients with effort angina by transesophageal atrial pacing two-dimensional echocardiography. liceto S, Caiati C, Piccinni G, Tota F, De Martino G, Marangelli V, Rizzon P. Cardiologia (Italy), Dec 1990, 35(12) p1023-6. Transesophageal atrial pacing (TAP) 2D echocardiography was performed after placebo (P) and gallopamil (G) (0.03 mg/kg iv) in 12 patients with stable, reproducible, effort angina. If compared to P study, during G the following changes were observed: 3 out of the 12 patients did not experience angina, time to ST-1mm increased from 5.3 +/- 1.3 to 6.6 +/- 1.6 min (p less than 0.05), wall motion score was improved both at 130 b/min (15.3 +/- 4.1 drug P, 17 +/- 4.8 drug G, p less than 0.01) and at 150 b/min (10.9 +/- 5.7 drug P, 12.8 +/- 6.3 drug G, p = 0.07). In conclusion, gallopamil has a beneficial effect on atrial pacing induced ischemia: it increases pacing time to ischemic threshold and reduces during ischemia the extent of dysfunctional myocardium.
Prediction of cardiac events after uncomplicated myocardial infarction by cross-sectional echocardiography during transesophageal atrial pacing. Iliceto S, Caiati C, Ricci A, Amico A, D'Ambrosio G, Ferri GM, Izzi M, Lagioia R, Rizzon P.University of Bari, Italy. Int J Cardiol 1990 Jul;28(1):95-103. Atrial pacing can safely be utilized shortly after myocardial infarction. To evaluate the prognostic value of wall motion abnormalities induced by such pacing 83 consecutive patients with recent uncomplicated myocardial infarction underwent transthoracic cross-sectional echocardiography during transesophageal atrial pacing and upright bicycle exercise stress test. Patients were followed-up for 14 +/- 5 months. During the atrial pacing and the echocardiography, patients were defined at high risk if abnormalities of wall motion were detected in left ventricular regions remote from the infarcted area. Then, during the exercise stress test, high risk patients were those with ST segment depression > 1 mm. On the other hand, patients were considered to be at low risk if they had no abnormalities of wall motion during atrial pacing in remote regions or, in the case of the stress test, if they did not develop ST depression greater than or equal to 1 mm. Of the 83 patients, 21 had major cardiac events during the period of follow-up. Cardiac events occurred in 15/23 (65%) and 5/60 (8%, P < 0.001) patients assigned to the groups adjudged to be at high and low risk, respectively, on the basis of echocardiographic results. Exercise testing was less reliable in identifying patients at risk of future cardiac events. Major events occurred in only 6 of the 19 patients with a positive stress test (32%, P < 0.05 vs positive stress echocardiography) and in 14 of the 64 patients with a negative exercise stress test (22%, P = NS vs positive exercise stress test, P < 0.05 vs negative atrial pacing echocardiography).
Prediction of the extent of coronary artery disease with the evaluation of left ventricular wall motion abnormalities during atrial pacing. A cross-sectional echocardiographic study. Iliceto S, Papa A, D'Ambrosio G, Amico A, Sorino M, Coluccia P, Rizzon P. Int J Cardiol 1987 Jan;14(1):33-45. In patients with coronary artery disease, left ventricular performance during stress is affected by the degree of coronary stenosis. In order to verify whether there exists a relationship between the extent of wall motion abnormalities detectable during atrial pacing and the degree of coronary obstruction, 76 patients, without previous myocardial infarction, were studied. Each patient underwent cross-sectional echocardiography during transesophageal atrial pacing and exercise electrocardiography before coronary angiography. Of the 76 patients, 46 had significant coronary artery disease (stenosis greater than or equal to 75% of at least one major coronary vessel), while 30 had normal coronaries or a stenosis of less than 75%. Eighteen patients had single-, 14 had two- and 14 had three-vessel disease. For each patient a coronary score was obtained: the score used took into consideration the site, number and severity of the stenosis. This score was then correlated with the wall motion score, obtained from the analysis of 9 segments of the left ventricle. A weak correlation was obtained between wall motion score at rest and coronary score (r = -0.42), while the correlation between coronary score and the difference between wall motion score at rest and during transesophageal atrial pacing was slightly better (r = 0.53); this correlation further improved if wall motion score during pacing was considered (r = -0.63). If the patients with discordant diagnostic tests (echocardiography during transesophageal atrial pacing and exercise electrocardiography) were excluded, the correlation coefficient between coronary score and wall motion score during pacing increased even more (r = -0.77). In conclusion: (1) analysis of wall motion of the left ventricle during atrial pacing is useful for the non-invasive evaluation of the severity of coronary disease; (2) cross-sectional echocardiography during atrial pacing, apart from being a useful diagnostic tool, is also a help in judging the degree of severity of coronary artery disease.
On-line assessment of left ventricular function by automatic border detection echocardiography during rest and stress conditions. Marangelli V, Pellegrini C, Piccinni G, Perez-Ayuso MJ, Gaglione A, Iliceto S, Rizzon P. Universita degli Studi, Bari. Cardiologia 1993 Nov;38(11):701-12. A new echocardiographic system, automatic boundary detection (ABD) echocardiography, provides automatic on-line quantification of the left ventricular cavity area. To assess the potential of ABD echocardiography in measuring left ventricular dimensions and detect stress-induced changes in left ventricular function, we studied 25 patients. Thirteen were studied to compare left ventricular cavity areas and fractional area change by using 2DE and ABD echocardiography during routine studies in multiple views; 12 patients were studied during transesophageal atrial pacing by ABD-echocardiography in 4-chamber or short-axis views. End-diastolic and end-systolic left ventricular areas measured by ABD echocardiography were not significantly different from two-dimensional ones for all the echocardiographic views, except the apical 4-chamber view; fractional area change values obtained with ABD were slightly lower than 2DE ones, although not significantly. High correlation values were found between the 2 techniques for end-diastolic area (r = 0.94, SEE = 3.69 cm2), end-systolic area (r = 0.90, SEE = 4.49 cm2) and fractional area change (0.73, SEE = 9.7%); similar results were obtained for each single echocardiographic view. A decrease was found from rest to peak-pacing in end diastolic area (25.2 +/- 5.1 cm2 vs 21.1 +/- 4.3 cm2, p < 0.003), end systolic area (16.2 +/- 6.0 cm2 vs 14.8 +/- 5.3 cm2, p < 0.016) and fractional area change (38.5 +/- 12.7% vs 31.8 +/- 9.6%, p < 0.003) with a return to baseline values in post-pacing (26.3 +/- 4.3 cm2 and 17.0 +/- 5.4 cm2 and 37.3 +/- 11.3%, p < 0.003 vs peak-pacing, NS vs rest for each parameter).
Characteristics of the changes in echocardiographic indicators of the electric cardiac pacing in alcoholics. Anikin VV. Klin Med (Mosk) 1991 Feb;69(2):44-6. To specify cardiovascular function in alcoholics (74 males capable for work by their age) of stage II, they under went M-mode ECG at the height of the rhythm induced by transesophageal pacing. One third of the examinees demonstrated worsening of the left ventricular contractility evident from reduced ejection fraction (by 17.1%) and shorter anteroposterior size of the left ventricle (diminution by 18.1%). Paradoxical movement of the interventricular septum in the systole emerged in one fifth of the patients at the height of the stimulation. It is believed important to identify a group of patients with initially abnormal intracardiac hemodynamics (13.6%). They suffered further deterioration of myocardial contractility. The study of ECG findings at the height of atrial stimulation detects latent alcoholic myocardiodystrophy.
Stress echocardiography in localization of coronary atherosclerosis and assessment of it severity. Burduli NM, Buziashvili IuI, Kharitonova NI, Matskeplishvili ST. Klin Med (Mosk) 1998;76(8):22-4. 193 patients with coronary heart disease were examined to study potentialities of noninvasive diagnosis of coronary artery lesions, their location and severity using transesophageal echocardiography in combination with transesophageal stimulation. This method of stress-test proved highly sensitive (89%) and specific (84%) in noninvasive diagnosis of both location of coronary atherosclerosis and its severity (stenosis, subtotal stenosis, occlusion) and extension.
Alternative approaches in stress echocardiography. Kamensky G, Plevova N, Slavicek F. Bratisl Lek Listy 1990 Dec;91(12):874-7. The authors' own experience as well as literary information on stress echocardiography in diagnosis of ischemic heart disease is presented. Besides dynamic postexercise echocardiography, which they consider to be the most adequate form of stress echocardiography, the authors analyze the possibilities of so-called alternative approaches, i.e. dipyridamole echocardiographic test and the use of transesophageal atrial pacing. The results of the three echocardiographic stress modalities show that their overall informative value is comparable. The practical performance is most favorable in the pharmacologic test, the highest safety is warranted in transesophageal atrial pacing, and tolerance proved to be best in the dynamic postexercise test. On choosing the actual stress modality, the authors recommend to weigh the advantages against the drawbacks before deciding on the approach of choice in the given situation so as to obtain optimal results.
Detection of multiple lesions of the coronary arteries in patients after myocardial infarction. Data of two-dimensional stress echocardiography during the test of transesophageal atrial electric stimulation. Chikvashvili DI, Karpov IuA, Ashmarin IIu. Biull Vsesoiuznogo Kardiol Nauchn Tsentra AMN SSSR 1987;10(2):56-62. The method of two-dimensional stress echocardiography with transesophageal atrial electrostimulation was used for determination of patients with high risk of complications among those who had survived myocardial infarction. The results of the test were compared to the degree of the coronary artery lesion. The highest sensitivity of the method (94%) in identification of patients with 2 or 3 involved coronary arteries was registered when appearance of new areas with damaged local contractility was used as a criterium. When depression of the ST segment for more than 2 mm or decrease of the left ventricular total ejection fraction for more than 5% was used as a criterium, the sensitivity of the method was correspondingly 72 and 78%.
Myocardial ischaemia un-masked by transesophageal atrial pacing combined with two-dimensional transthoracic echocardiography in a pediatric patient: a case report. De Caro E, Pongiglione G Istituto G. Gaslini, Servizio di Cardiologia, Genova, Italy. Int J Cardiol 1998 Sep 30;66(2):133-5. We describe a case of a child operated on for an anomalous origin of the left coronary artery from the pulmonary artery and proximal hypoplasia of the anomalous coronary, in whom residual inducible myocardial ischaemia was detected by means of transesophageal atrial pacing combined with transthoracic echocardiography.
The possibilities of using ambulatory stress echocardiography with transesophageal atrial stimulation. Ziablov Iu I, Trivozhenko AB. Ter Arkh 1997;69(4):21-2. Stress echocardiography (duplex regimen echocardiography combined with transesophageal pacing) was performed outpatiently in 64 subjects. Among them there were patients with verified angina of effort and ischemic heart disease suspects. The test reached diagnostic criteria in 85% of the examinees. Significant signs of coronary insufficiency were recorded in 12% of patients with doubtful evidence obtained at bicycle ergometry. This method is proposed as an alternative (in addition to stress ECG tests) variant of outpatient diagnosis of coronary insufficiency in doubtful cases and to assess coronary reserve in patients with verified ischemic heart disease.
Doppler echocardiography during transesophageal atrial pacing in the detection of coronary artery disease. Vaskelyte JV, Navickas RS, Kinduris SJ. Lithuania. Int J Card Imag 1994;10(1):61-5. The aim of this study was to assess the applicability of the Doppler echocardiogram (EchoKG) during transesophageal atrial pacing (TAP) with respect to the detection of coronary artery disease (CAD). Aortic flow peak velocity (PV), mean acceleration (MA), stroke distance (SD), minute distance (MD) and time to PV were measured using pulsed Doppler EchoKG during sinus rhythm and at pacing rates of 120 and 140 bpm in 11 patients, taken as subjects, with CAD defined by coronary arteriography and 15 patients without CAD (the control group). Similar changes of PV, SD, MD and time to PV during TAP were observed in subjects with and without CAD. Only changes of MA were different between subjects with and without CAD:MA during TAP remained unchanged in the control group and decreased from 1055.2 +/- 49.7 cm/s2 (baseline) to 829.0 +/- 55.9 cm/s2 at pacing rate 140 bpm (p 0.05) in subjects with CAD. On the basis of these data we suggest a new criterion for the detection of hemodynamically significant CAD: decrease of MA at a pacing rate of 140 bpm 15% of initial value. Its specificity and sensitivity in the detection of CAD were respectively 87% and 82%. We conclude that the Doppler EchoKG during TAP is a relatively simple and reliable method for the diagnosis of CAD, and that the response of the Doppler EchoKG parameter of MA to TAP is a sensitive and specific index, useful for the detection of significant coronary artery stenosis.
Myocardial ischaemia un-masked by transesophageal atrial pacing combined with two-dimensional transthoracic echocardiography in a pediatric patient: a case report. De Caro E, Pongiglione G. Istituto G. Gaslini, Servizio di Cardiologia, Genova, Italy. Int J Cardiol 1998 Sep 30;66(2):133-5. We describe a case of a child operated on for an anomalous origin of the left coronary artery from the pulmonary artery and proximal hypoplasia of the anomalous coronary, in whom residual inducible myocardial ischaemia was detected by means of transesophageal atrial pacing combined with transthoracic echocardiography.
Effects of acute myocardial ischemia on intramyocardial contraction heterogeneity : A study performed with ultrasound integrated backscatter during transesophageal atrial pacing. Colonna P, Montisci R, Galiuto L, Meloni L, Iliceto S. Circulation 100(17):1770-6, 1999. Background-Subendocardial thickening is greater than subepicardial thickening and acute myocardial ischemia mainly impairs the former. Integrated backscatter cyclic variations (IBScv) reflect regional myocardial contractility and are blunted during myocardial ischemia. We hypothesized that stress-induced myocardial ischemia mainly affects subendocardial IBScv. Methods and Results-Multiplane transesophageal echocardiography and simultaneous atrial pacing were performed in 12 patients without coronary artery disease (CAD) and in 25 with significant CAD. In a transgastric 2-chamber view, we calculated IBScv in subendocardium and subepicardium and a heterogeneity index, both at rest and at peak-pacing. In 27 myocardial segments of patients with normal coronary arteries, and in 16 myocardial segments supplied by coronary artery without significant stenosis in patients with CAD, there was a transmural gradient of IBScv at rest and the heterogeneity index did not change during all the protocol steps. In the 53 myocardial segments related to a significantly narrowed coronary artery, the transmural gradient of IBScv, present at rest, significantly decreased at peak-pacing because of subendocardial blunting, but promptly recovered 5 seconds after pacing interruption. Moreover, the myocardial thickening at rest and peak pacing correlated with the subendocardial IBScv behavior and not with the subepicardial one. Conclusions-IBScv are greater in the subendocardium than in the subepicardium. Atrial pacing stress test does not affect IBScv in segments supplied by nonstenotic coronary arteries, whereas it affects segments supplied by diseased coronary arteries, blunting exclusively subendocardial IBScv. Heterogeneity of IBScv intramyocardial changes caused by stress-induced ischemia must be taken into account when using IBScv for investigating myocardial ischemia.
Acute hemodynamic deterioration during rapid atrial pacing in patients with hypertrophic cardiomyopathy. Nakatani M, Yokota Y, Yokoyama M. Kobe University School of Medicine, Japan. Clin Cardiol 1996 May;19(5):385-92. BACKGROUND AND HYPOTHESIS: Supraventricular tachycardia and ventricular tachycardia are often observed in patients with hypertrophic cardiomyopathy (HCM) and they often alter the clinical features of HCM. We examine the influence of supraventricular tachycardia on cardiac function and assess the clinical characteristics of patients with HCM. METHODS: We studied 32 patients with HCM and 8 normal volunteers using echocardiography under transesophageal rapid atrial pacing. RESULTS: Presyncope-associated hypotension was observed during rapid atrial pacing in 8 HCM patients, but in none of the normal controls. During rapid atrial pacing (144 +/- 8 beats/min in HCM, 146 +/- 5 beats/min in controls), systolic blood pressure (SBP), the product of left ventricular filling volume (FV) and heart rate, and fractional shortening (%FS) in the HCM patients decreased significantly compared with the basal values (138 +/- 19 mmHg vs. 99 +/- 24 mmHg, 5.0 +/- 1.2 l/min vs. 2.9 +/- 0.9 l/min, 41.7 +/- 6.2% vs. 35.2 +/- 6.0%, respectively), but these decreases were not observed in normal controls. The decrement of SBP during rapid atrial pacing in HCM patients with a history of syncope was more marked than that in those without such history. The decrement correlated positively with the indices of left ventricular hypertrophy (maximal wall thickness and wall thickness index) and with %FS, and correlated negatively with the endsystolic left ventricular diameter at rest. CONCLUSIONS: In some patients with HCM, supraventricular tachycardia causes marked hemodynamic deterioration that may be related to a history of syncope, marked hypertrophy, hyperkinesis, small cavity size, and small filling volume of the left ventricle.
Early experience with esophageal pill electrode atrial pacing in the diagnosis of coronary artery disease--a trend toward improved specificity compared to treadmill exercise. Matthews RV; Haskell RJ; Blagotic M; Laks MM. UCLA Medical Center. J Electrocardiol, 1987, 20 p157-62. Esophageal pill electrode pacing, treadmill exercise and coronary angiography were performed in 23 patients with chest pain. Atrial pacing produced fewer false positive studies resulting in higher specificity compared to treadmill exercise. Some possible explanations of the improved specificity are the better quality tracings obtained with atrial pacing and the increased control of the heart rate and blood pressure response during atrial pacing as opposed to treadmill exercise. This preliminary study suggests that esophageal pill electrode atrial pacing tachycardia studies may be a reasonable alternative to treadmill exercise testing in the noninvasive diagnosis of coronary artery disease.
A comparative evaluation of the importance of transesophageal electrical stimulation of the left atrium and of bicycle ergometry in the diagnosis of ischemic heart disease in patients with arterial hypertension. Azizov VA, Gorshkov ASh, Kivaeva GM, Gadzhiev RSh, Bekzhigitov SB, Arabidze GG, At'kov OIu. Kardiologiia 32(7-8):37-40, 1992. To make a comparative assessment of transesophageal left atrial pacing (TLAP) and bicycle ergometry (BE) in the diagnosis of coronary heart disease (CHD) in patients with arterial hypertension (AH) of different origin, the authors examined 56 patients. The patients underwent TLAP and selective coronary angiography, of them 39 patients had BE testing. No significant differences were found in their specificity (73 and 78%) and sensitivity (92 and 81%) between TLAP and BE, respectively. The maximum heart rate in CHD patients with AH was significantly higher (130 +/- 6 per min) during TLAP than that in BE (112 +/- 5 per min, p > 0.05), ischemic changes occurring at the same value of double product despite the mode of myocardial ischemia induction in these functional tests (240 +/- 10 and 236 +/- 12 arbitrary units, respectively; p < 0.05). The mean systolic blood pressure was higher in TLAP and in BE (210 +/- 10 and 185 +/- 8 mm Hg). This follows that TLAP and BE finding are comparable and no profound changes occur in TLAP, hence it can be recommended for wide application in the diagnosis of CHD in AH patients.
Exercise echocardiography with left atrial stimulation: advantages and limitations of the method. Plonska E, Kornacewicz-Jach Z, Puchala M. Kliniki Kardiologii PAM w Szczecinie. Pol Tyg Lek 1996 Mar;51(10-13):175-8. Exercise echocardiography seems a relatively reliable diagnostic technique for evaluation of patients with coronary artery disease. The prognostic aspects of the stress echo have widely been documented with the use of various stressors (exercise, dipyridamole, dobutamine, pacing). Rapid atrial pacing echocardiography is highly specific and sensitive technique for the detection of the coronary disease, especially in patients who are unable to perform an active stress test. This technique minimizes the factors decreasing image quality during exercise (chest wall movements and hyperventilation). Exercise echocardiography is safe, relatively cheap, and can be done in every hospital.
Left ventricular function in patients with ischemic heart disease at the moment of acute myocardial ischemia induced by transesophageal cardiac electrostimulation. Savchenko AP, Smirnov AA, Liakishev AA, Mamytova ZZh, Abugov SA, Kozlov SG. Ter Arkh 1993;65(12):30-4. Repeat transvenous multiphase left ventriculography was performed in 14 patients with coronary stenosis diagnosed by clinical and angiographic findings. The procedure was conducted before and in the course of transesophageal pacing. The latter provoked acute myocardial ischemia responsible for a wide range of left ventricular dysfunctions which are analyzed in the paper in terms of cardiomanometry parameters, cardiocycle energetic balance, diastolic function and local motions of the camera walls.
Use of loading tests to detect silent myocardial ischemia. Elkonin AB, Vasiagin AI, Vertkin AL. Kardiologiia 1992 Sep;32(9-10):34-6. A total of 74 patients with postinfarct cardiosclerosis (PC) and stable angina (SA) were examined by Holter monitoring, bicycle ergometry, echocardiography and 201Tl chloride myocardial scintigraphy and loading tests (transesophageal cardiac pacing and isometric hand exercise test). The detection rate for silent myocardial ischemia (SI) was found to be 57.1% with Holter monitoring, 52.3% by bicycle ergometry, 62.5% with echocardiography, 100% with myocardial scintigraphy with loading test and 88.8% with that without the loading test. The detection rate for PC was 33.9, 32.0, 64.7, 81.8, and 56.7%, respectively. Higher SI detection rates in postinfarct patients were more frequently observed when echocardiography and myocardial scintigraphy in combination with loading tests in patients with PC without angina. The efficiency of SI detection in patients with various coronary heart disease increases when loading tests are employed. The loading tests in echocardiography and myocardial scintigraphy ensure the most complete detection of SI in postinfarct patients without angina.
Transesophageal atrial stimulation--a test for myocardial ischemia. Jovic A, Nekic-Borcilo M, Troskot R, Nekic D, Knezevic A, Rados G. Lijec Vjesn 1994 Jan-Feb;116(1-2):35-40 The aim of the present study was to determine clinical value and the feasibility of transesophageal atrial pacing (TAP) in diagnosing myocardial ischemia in patients with coronary artery disease (CAD). Forty patients with CAD and with significant ST-segment depression in a standard 12-lead ECG during bicycle-stress testing underwent TAP. Rapid atrial stimulation was performed by using a very flexible six-polar polyurethane pacing lead introduced through the nares into the esophagus and connected to the stimulator allowing selection of rate, output voltage and pulse duration. The satisfactory atrial pacing was obtained by 28 +/- 6 V output and 7 +/- 1 ms pulse duration. Of 40 patients who underwent TAP, ischemic ECG changes were induced in 35 (u = 2,24 p < 0,05) and were very similar to those that occurred during bicycle-stress testing according to their intensity and distribution and affected ECG leads with comparable peak rate-pressure products. This suggests comparable sensitivity of TAP and bicycle-stress testing in discovering myocardial ischemia in CAD patients. Four patients had negati