Cardiovascular complications during exercise training of cardiac patients.

The occurrence of major cardiovascular complications during exercise training of cardiac patients in 30 cardiac rehabilitation programs in North America was determined by questionnaire. These programs conducted medically supervised cardiac exercise classes in 103 locations and reported information on 13,570 participants who accumulated a total of 1,629,634 patient hours of supervised exercise. Cardiovascular complications were reported as nonfatal or fatal and included cardiac arrest, myocardial infarction and other. A total of 50 cardiac arrests were observed during exercise, 42 of which were successfully resuscitated while eight were fatal. Seven myocardial infarctions were reported; five were nonfatal and two were fatal. Four other fatalities were reported due to acute cardiopulmonary disorders. The average complication rate for all programs was one nonfatal and one fatal event every 34,673 and 116,402 patient hours of participation, respectively. Complication rates are lower in programs which continuously monitor the electrocardiogram during exercise and are lower when only the experience since 1970 is evaluated. These data support the recommendation that medically prescribed and supervised exercise can be performed reasonably safely by medically selected cardiac patients.