Pacing echocardiography regional wall motion, left ventricular dimension and R wave amplitude in patients with angina pectoris.

Abstract

SUMMARYIn view of the fact that stable echocardiograms are easily obtained during atrial pacing, pacing echocardiography was performed to evaluate the usefulness for detecting regional wall motion abnormalities during pacing-induced ischemia and to investigate the relationship between changes in the R wave and left ventricular dimension. The patients were 12 cases of angina pectoris (10 of coronary artery disease; CAD, and 2 of coronary patent aortic valvular disease; AVD) and 6 control cases. Simultaneous recording of two-dimensional and M-mode echocardiograms and electrocardiograms was done before, during and after the atrial pacing at increasing heart rate until angina appeared or the heart rate of at least 140/min was reached. In 12 angina cases, angina and ST depression were induced in 10 and 11, respectively. Excursion of the interventricular septum (IVS) decreased during pacing-induced ischemia in 6 of 7 CAD cases, in which the left anterior descending coronary artery was significantly stenosed (more than 75%). Excursion of the left ventricular posterior wall (LVPW) decreased during pacing-induced ischemia in 4 of 7 CAD cases, in which the vessels giving rise to posterior descending coronary artery were significantly stenosed (more than 75%). In 2 AVD cases, excursion of both IVS and LVPW decreased during ischemia. Left ventricular end-diastolic dimension (LVEDD) increased in only 2 angina cases, although R wave amplitude increased in 6 angina cases. SUBJECTS AND METHODS Subjects:Six patients (4 males and 2 females) aged 29 to 57 (mean 47.2 years) with negative exercise electrocardiograms were studied as control cases. There were 2 cases with asymmetric apical hypertrophy, 2 with chest pain of uncertain etiology, one with mitral valve prolapse and one without clinical evidence of heart disease. Coronary angiography was performed in the 2 cases with negative results (Table I) pain appeared after atrial pacing was stopped (see Fig. 8).R wave and the greatest left ventricular diameter particularly when the heart rate was high, so that LVEDD was measured at the greatest left ventricular diameter in such cases. Because M-mode echocardiograms were recorded at the level of the papillary muscles in most cases , LVEDD was different from "LVEDD" obtai ned in the standard way at the level of the tip of the mitral valve. Thus, in the present study, LVEDD was compared intraindividually but not interindividually. The method of the present study is ascertained by the fact that, in patients with coronary artery disease , left ventricular enddiastolic volume can be estimated from LVEDD obtained by M-mode echocardiography, if ventricular aneurysms do not exist .23) Six electrocardiographic leads (I, II, III , V4, V5, V6) were monitored continuously before, during and after atrial pacing . Degree of the ST depression and amplitude of the R wave were measured in the lead where the 6 TAKENAKA, ET AL.Jpn. Heart J. J anuary 1982 Fig. 1. Control case 6. M-mode echocardiograms and ECGs (V5) before, during and after atrial pacing...