AFTER EXERCISE TRAINING IN SUBJECTS FOLLOWING MYOCARDIAL INFARCTION

Heart rate variability reflects the activity of autonomic nervous system. The aim was to evaluate the value ofshort-term spectral analysis of heart rate for monitoring the effects of exercise training on the autonomic nervoussystem in subjects following myocardial infarction. Short-term spectral analysis of heart rate variability wasperformed during standardised supine-standing-supine test in a group of 29 clinically stable patients after myocardialinfarction and the same test was repeated after 2 months of exercise training (ergometry or rapid walking).Each subject exercised at 60–80% of his maximal performance for 30 minutes once a day. Short-term spectralanalysis of heart rate variability was assessed in the frequency range of 0.02–0.5Hz involving very low frequency(VLF, 0.02–0.05Hz), low frequency (LF, 0.05–0.15Hz) and high frequency (HF, 0.15–0.5Hz) spectral bands. Theinfluence of exercise training on the autonomic nervous system was registered in the physically active group (n = 16)as a decrease in sympathetic response to standardised orthostatic load. In conclusions the regular exerciseinfluenced an altered neural autonomic regulation of heart rate in post-infarction patients shown by a decrease insympathetic activity in the short-term heart rate variability. This method enables monitoring of the effects ofphysical training on the autonomic nervous system in patients following myocardial infarction.