Role of endocrine factors in chronic congestive heart failure, with emphasis on catecholamines.

Changes in endocrine activity in response to tilting of the body were studied in 16 in-patients with various degrees of chronic congestive heart failure and one healthy subject. Norepinephrine and epinephrine excretion, plasma renin activity and plasma cortisol concentration were determined first in recumbency and then during 45 degree head-up tilting. The subjects were divided into three groups depending on the severity of heart failure. In recumbency urinary norepinephrine averaged 31.6 (standard deviation 12.7) ng/min in group 1 (controls), 54.9 +/- 25.3 ng/min in group 2 (NYHA class II--III) and 79.5 ng/min in group 3 (NYHA class IV). Thus the level of urinary norepinephrine increased with the degree of heart failure. In recumbency epinephrine excretion and plasma cortisol concentration were not different among three groups. Plasma renin activity was elevated in group 3. There was a significant positive correlation between the changes in plasma renin activity and epinephrine secretion (r = 0.67, p less than 0.01). The present study revealed that patients with slight to moderate congestive heart failure have a normal endocrine response to tilting while those in severe failure have only a slight response. It is probable that the augmented sympathetic nerve activity and increased circulating blood volume, already present in severe failure, allow for less hemodynamic change upon tilting.