[Changes in the atrial natriuretic factor and the renin-angiotensin-aldosterone axis induced by maximum exertion in subjects with a recent myocardial infarct].
To examine the effect of exercise-induced myocardial ischemia (EIMI) on atrial natriuretic factor (ANF), plasma renin activity (PRA) and aldosterone (PA), a maximal exercise test in 12 patients with recent acute myocardial infarction (AM) was performed. ANF, PRA and PA were measured by radioimmunoassay at baseline, peak-exercise and at 15 min after recovery. Four patients developed EIMI (group I) and 8 patients did not (group II). ANF increased in all patients from baseline to peak-exercise (27.7 +/- 9.5 pg/mL vs 92.7 +/- 26.7 pg/mL, p less than 0.0005) and it was still elevated 15 min after recovery. Baseline ANF was similar in both groups while at peak-exercise it was higher in group. I than in group II (112 +/- 15 pg/mL vs 82 +/- 26 pg/mL p less than 0.05). After 15 min of recovery, ANF was higher in group I than in group II (67 +/- 20 pg/mL vs 32 +/- 10 pg/mL, p less than 0.01), resulting higher than at baseline only in group I (p less than 0.05). PRA and PA also increased during exercise but their values rose more slowly and were the same in both groups. Thus, ANF, PRA and PA increase during exercise in patients after AMI, and EIMI is associated with higher ANF plasma levels.