[Clinical and functional assessment of electric heart instability in patients with painless myocardial ischemia].

Markers of electric myocardial instability were studied in 82 patients during painless episodes of coronary heart disease (CHD). Clinical examination was supplemented by 12-lead ECG, 24-hour ECG monitoring, functional tests, echocardiography, signal-averaged ECG, recording of LVP, analysis of cardiac rhythm variability, and assessment of ventricular repolarization time. It is concluded that a combination of 24-hr ECG monitoring and functional tests (veloergometer) is indispensable for diagnostics of CHD and the evaluation of the patient"s condition. Daily dynamics of myocardial ischemia and the number of its painless episodes are shown to correlate with the results of signal-averaged ECG, Q-T dispersion and LF/HF ratio. Patients with painless CHD show enhanced frequency of myocardial infarction with the Q-wave, high-grade ventricular extrasystole, and LVP coupled to disordered autonomous vegetative control of the sinus rhythm.