201Tl myocardial scintigraphy was performed in 29 patients with coronary heart diseases and silent myocardial ischemic episodes revealed during a long-term monitoring of ST segment. The painless ST segment depression episodes and long high-amplitude painless ST segment elevations were found to be indicative of a significant severity of pathological processes in the myocardium. A 12-day nicardipine monotherapy produced antianginal and hypotensive effects and contributed to decrease in the frequency, duration, and amplitude of silent ST-segment depressions and in the duration of silent ST-segment elevations.