PLASMA-CATECHOLAMINES AFTER CARDIAC INFARCTION

Abstract

Plasma noradrenaline and adrenaline were measured in fifty men after cardiac infarction and in fifty controls. Noradrenaline levels were significantly higher in the cardiac patients compared with the controls, but adrenaline levels were similar in the two groups. The catecholamine levels were analysed for the patients in relation to the incidence of dysrhythmias. Compared with patients who had no complications, patients with atrial dysrhythmias or early ventricular dysrhythmias had higher noradrenaline concentrations in their plasma. There was no such difference for patients with late ventricular dysrhythmias, and adrenaline levels were unremarkable. The raised noradrenaline levels are not thought to be related to stress because six other patients undergoing the stressful procedure of cardiac catheterisation had low levels. High noradrenaline levels in three racing drivers shortly after a race suggest that the beta-adrenergic effect of noradrenaline does not lead to ventricular dysrhythmias in the presence of a healthy heart. It is concluded that there is an increased noradrenaline release after myocardial infarction and that this is related to the development of serious dysrhythmias.