Neurohormonal activation and the response to converting enzyme inhibitors in congestive heart failure.

The neurohormonal vasoconstrictor systems are frequently activated in patients with congestive heart failure, and they make important contributions to characteristic abnormalities in vasoconstriction. In 177 patients with congestive heart failure, however, there was a widespread distribution of levels of plasma renin activity and plasma norepinephrine, indicating that activation of the renin-angiotensin system and the sympathetic nervous system was not uniform. Furthermore, there were only weak correlations between plasma renin activity and plasma norepinephrine and hemodynamic measurements, age, and renal function, indicating that activation of these systems is complex and determined by many other factors. The converting enzyme inhibitors have beneficial effects on the hemodynamic abnormalities of patients with heart failure, with reductions in arterial tone and preload as well as increases in cardiac output. Their long-term effects on markers of the renin-angiotensin system, however, and their interactions with the sympathetic nervous system and atrial natriuretic factor are less well defined.