Plasma catecholamines in patients with acute myocardial infarction and in cardiac arrest.

Plasma catecholamine concentrations in cardiac arrest (ventricular fibrillation and asystole) are significantly higher than after myocardial infarction. The levels reached are well above those normally required to stimulate cardiac activity. Possible reasons for the failure of the myocardium to respond to the catecholamines are discussed and the rationale for giving more catecholamines is questioned.