The incidence of ventricular arrhythmias in rehabilitated post-myocardial infarction (MI) patients with left ventricular dysfunction included in a long-term rehabilitation program was assessed and compared with that in similar patients who were not in such a program. Thirty-eight post-MI patients (2 to 19 years after the acute event) with ejection fraction <40% were investigated by 48-hour Holter monitoring. They were divided into the following 3 groups: group I, 11 patients who underwent arm training for 60 months; group II, 11 patients who underwent calisthenics for 36 months; and group III, 16 patients who were not in any rehabilitation program; the age of the patients was 61 ± 7, 61 ± 6 and 61 ± 9 years, respectively, (p = not significant). Ejection fraction at rest was 31 ± 9 for group I, 29 ± 7 for group II, and 29 ± 7 for group III (p = not significant). There were no significant differences concerning the location of Ml, and antiarrhythmic treatment received by patients from all groups. At the conclusion of 48-hour Holter monitoring, 2 blood samples were obtained for assessment of norepinephrine (at rest and after postural change). Quality of life was determined by a detailed questionnaire, including questions concerning social activity, life satisfaction and sexual function. After 36 and 60 months, an improvement in hemodynamic condition of patients in group I was noted. Quality of life was higher in the rehabilitated patients, with enhanced emotional stability, satisfaction with work and social life, and a high percentage of return to work (82 vs 40%). The lowest levels of norepinephrine were found in group I and the highest in group III (p < 0.02), whereas they were within normal limits in group II. Isolated ventricular premature beats (>60/hour) were found in 1 (10%), 2 (18%) and 9 (56%) patients (p < 0.05), and complex ventricular arrhythmias in 4 (33%), 3 (27%) and 12 (77%) patients (p < 0.05) in groups I, II and III, respectively. Nonsustained ventricular tachycardia was recorded in 2 patients (17%) from group I with 4 episodes, 2 patients (17%) from group II with 7 episodes, and 6 patients (37%) from group III with 24 episodes (p < 0.03); 3 of the latter patients had complex ventricular arrhythmias also. It appears that a long-term comprehensive rehabilitation program decreases neuroadrenergic activity, the arrhythmogenic effect of catecholamines and consequently, the incidence of ventricular arrhythmias.