[Course of coronary disease. Evaluation of prognosis and progression of coronary insufficiency with atrial pacing and ergometry].

Significant reduction of angina threshold (145 Imp./min to 134 Imp./min) and increase of ST-segment depression (0.13 to 0.17 mV) indicating progression of coronary artery disease was seen in 34 subjects studied by atrial pacing at intervals betion (0.22 mV to 0.12 mV) during exercise, which correlated significantly with decrease of heart rate (121 to 110 beats/min), is interpreted as consequence of diminished sympathetic activity and myocardial O(2)-demand. The change of hemodynamic parameters during controlled exercise does not allow evaluation concerning the progress of coronary artery disease, whereas cardiac stress test with atrial pacing is reproducible. There was no difference in relation to reduction of angina threshold between the group after combined longterm medication with nitrate and ss-blocking agent and the control group. Plasma lipid abnormalities were predictive of subsequent reduction of angina threshold. Severe 2 and 3 vessel obstruction was seen more frequently in patients exhibiting reduction of angina threshold. Level of uric acid, obesity, hypertension, age, combination of risk factors, the initially studied myocardial lactate production and angina threshold during exercise and atrial pacing had no predictive value concerning reduction of angina threshold.