Seventy male subjects participated in a six session study of feedback mediated heart rate modification. Three groups of subjects were compared: college students, patients with ischemic heart disease, and healthy males, age matched to the patients. The groups did not differ in heart rate during rest or in response to a perceptual motor tracking task. However, the college students produced significantly larger changes in cardiac rate than the other two groups when instructed to modify heart rate (speed or slow) and provided with exteroceptive feedback. The patients showed the poorest overall feedback performance. These differences between groups were greater for speeding than for the slowing task. Relationships were explored between feedback performance and resting heart and respiration rate, drug regime, and personality questionnaires. The results were consistent with the hypothesis that interdependence between psychological stimuli and cardiovascular events is reduced in heart disease.