[Activity of the sympathetic nervous system and of the renin-angiotensin system in the acute stage of myocardial infarction].

We studied sympathetic and renin-angiotensin systems activity in a series of 175 patients suffering from acute myocardial infarction. These two systems were both overactivated especially in the cases complicated by hemodynamically documented left heart failure. The response of these systems to acute heart failure was in the same range for patients younger or older than 65 years and the witness (norepinephrine and plasma renin levels) of sympathetic and renin-angiotensin activities were good independent prognostic factors of in-hospital mortality.