[Impact of exercise test on signal-averaged ECG in patients with myocardial infarction]

To examine the impact of exercise test (bicycle ergometry) and exercise-induced transient ischemic changes in ST segment on signal-averaged ECG parameters, the authors studied a homogeneous group including 65 patients (62 males and 3 females) with a 2-3-week history of primary myocardial infarction. The findings showed that induced myocardial ischemia caused no significant changes in signal-averaged ECG and late potentials, exercise might induce late potentials without clear-cut ECG signs of myocardial ischemia. It was also indicated that exercise-labile late potentials were significantly more frequently associated with the development of ventricular arrhythmias than steady late potentials.