Cardiac Awareness in Infarct Patients and Normals

It has been argued that many subjects may have low awareness of visceral sensations because such feedback is of little relevance and salience in normal activity. This experiment examines awareness of cardiac sensations (heartbeats) in a group of 13 subjects, aged 37–67 yrs, all of whom had myocardial infarcts within the preceding 6 yrs previous to the experiment. Cardiac awareness was contrasted with the performance of a gender and age matched noncardiac control group on 80 Whitehead type discrimination trials. It was hypothesized that since rehabilitated cardiac patients frequently profess extreme sensitivity to their heart's activity and often experience benign arrhythmias which cause them to focus attention on their heart rate, that this group would show greater awareness of heartbeats than controls. The results clearly show that cardiac patients are no better able to discriminate true from false trials than are normals. Only one of 26 subjects showed above chance levels of discrimination, which is much lower than the percentage usually reported for young adult subjects. Respiration rate and amplitude, finger pulse volume, and heart period showed no differences between groups. The results suggest that although cardiac patients may feel aware of cardiac activity, they show no higher awareness of heartbeats during normal sinus rhythm than noncardiac controls.