Physiological cost of vocational activities after myocardial infarction

Oxygen consumption was measured during 30 min of work in 16 patients, after a myocardial infarction (anterior or posterior), and compared with 16 normal subjects, of the same age, involved in the same activities, in a steel factory. The VO2 at work of the patients was a little lower than in normals. The mean heart rate for 8 h was also a little lower in patients than in normals. The patients used a higher percentage of their residual capacity (VO2 max) as evaluated on a bicycle ergometer in the laboratory; the difference may be important between patients with a residual coronary insufficiency and controls. There are no important differences in the psychological attitudes of the two groups; the patient seems to be more motivated. From this study, based on a limited number of patients who had returned to work and had no complaints in daily life, it appears that the patients were working more 'economically' that the normals, that they are able to use a higher percentage of their residual physiological capacity and that the psychological attitude is comparable in the two groups towards work. Return to previous work should never be excluded a priori in post-infarction patients with good clinical progress.