Submaximal Exercise Testing

To examine the electrocardiographic response to exercise in an older population, 280 participants in a longitudinal study of cerebrovascular disease were tested. Subjects were randomly selected from the total 50 to 69-year-old population of Birmingham, Alabama. Approximately 60% of the participants reached a heart rate more than 80% of their predicted maximal heart rate. Subjects were divided into three groups on clinical grounds: (I) vascular disease, (II) risk factor(s) only, and (III) normal. Positive tests (at least 0.10 mv of ischemic ST-segment depression) were most frequent in group I (24%), though not significantly different from group II (19%) and group III (12%). Hypercholesterolemia was significantly associated with a positive exercise test only in those subjects with vascular disease. Nonspecific ST-T wave changes on the resting electrocardiogram were associated with a positive test in all subjects, but with only a borderline test in those subjects without vascular disease. No significant associations were noted between abnormal exercise test and either cigarette smoking or hypertension.