Stability and inter-relationships of hormone, haemodynamic and electrolyte levels in heart failure in man.

Relationships between clinical status, haemodynamic measurements, hormone and biochemical indices, and maintenance diuretic dose in patients with chronic cardiac failure, are not clear. This study assessed such relationships and their stability under standardized conditions in 21 hospitalized patients. The daily maintenance dose of frusemide correlated closely and in a positive fashion with plasma levels of renin activity, angiotensin II and aldosterone (P less than 0.001), and to a lesser extent with plasma noradrenaline. Although there was some overlap, patients most incapacitated by their heart failure had the highest circulating levels of renin activity, angiotensin II, aldosterone and noradrenaline. Plasma aldosterone correlated closely with concomitant angiotensin II levels (r = 0.70, P less than 0.001) but not with its other secretagogues ACTH (as reflected by plasma cortisol) or plasma potassium. Close positive correlations between angiotensin II and plasma levels of urea and creatinine (P less than 0.01) were observed. Both renin and angiotensin II showed positive relationships with right heart pressures, but were inversely related to cardiac index and arterial pressure. These results show close relationships between clinical and haemodynamic indices on one hand, and hormones on the other. The renin-angiotensin system appears to be the primary regulator of aldosterone under these conditions, and its activity relates closely to haemodynamic measurements and to the degree of azotaemia.