[Assessment of the diagnostic significance of R wave amplitude changes in patients with ischemic heart disease in computer-assisted monitoring analysis of ECG during treadmill test].

During treadmill exercise, 57 patients with documented coronary heart disease (CHD) were studied for the change patterns in R wave amplitudes in V5 lead by analyzing ECG on a computer. With exercise, 86% of CHD patients showed higher or no R wave amplitude changes, whereas 73.7% of healthy subjects displayed its lower changes. Increased or no R wave amplitude changes in CHD patients was accompanied by more marked quantitative ischemic parameters than their decrease. A significant correlation was found between higher R wave amplitude and extended exercise-induced myocardial ischemia. Decreased R wave amplitude was associated with local ischemic shifts. Comparison of the data obtained from the computer-assisted ECG analysis and radiocardiometric findings during the exercise test demonstrated that an increase m R wave amplitude in CHD patients was followed by higher cardiac volume, which indicated ischemic myocardial dysfunction.