[Arrhythmia and silent myocardial ischemia in patients after myocardial infarction]

In a group of 37 patients (30 men and 7 women aged from 36 to 67 years, men age 50.3) after a first acute myocardial infarction the frequency was analysed of the episodes of silent myocardial ischaemia with ST depression, and its correlation with arrhythmia was studied during outpatient ECG monitoring and exercise test on cycle ergometer. Outpatient ECG monitoring during 24 hours was done with a recorder Oxford Medilog MR-14 AM System 8-12 weeks after the onset of infarction. In the same patients the exercise test on cycle ergometer (KF-12 Medicor) was done by graded exercise method with workload increasing by 25 Watt every 3 minutes. The test was terminated after achieving 85% maximal heart rate or appearance of limiting signs. Each episode of ST depression by 1.0 mm or more lasting over 1 minute with horizontal or sloping ST depression 80 msec from point J was regarded in both cases as ischaemic. During outpatient ECG monitoring it was observed that 30 out of 37 (81.1%) had 138 episodes of ST depression, including 45 (32.6%) associated with pain and 93 (67.9%) painless (p less than 0.02). The mean maximal ST depression during painful and painless episodes was respectively 3.4 +/- 1.3 mm and 2.9 +/- 1.1 mm (p less than 0.03). Out of 30 patients 7 (23.3%) had 54 episodes of various arrhythmias, with bursts of ventricular ectopic beats, in one patient supraventricular tachycardia and in another one grade II atrioventricular block developed. These patients had also isolated ventricular ectopic beats. In 6 patients (20.0%) arrhythmia was temporarily associated with signs of ischaemia with ST depression.(ABSTRACT TRUNCATED AT 250 WORDS)