Amiloride improves hemodynamics in patients with chronic congestive heart failure treated with chronic digoxin and diuretics.

Potassium-sparing diuretics have been reported to decrease the positive inotropic effect of digoxin. We studied the hemodynamic effects of amiloride in patients taking digoxin for chronic heart failure. Eleven men with a history of congestive heart failure were studied in a double blind, cross-over, placebo controlled trial with the patients on digoxin alternating placebo with amiloride. After 7 days on the trial drug, a Swan-Ganz catheter was placed in the pulmonary artery and measurements made at rest and with increasing degrees of supine bicycle exercise. Right-sided and pulmonary artery wedge pressures and systemic arterial pressures, as well as cardiac outputs, were measured. After a 7 day washout period, placebo (P) and Amiloride (A) were switched and after 7 days on the therapy, a second hemodynamic study at rest and varying degrees of supine bicycle exercise was repeated. At rest there were no significant differences in the right-sided, pulmonary arterial wedge pressure or cardiac outputs between the patients on Amiloride (A) versus placebo (P). During exercise there were significant differences between (P) and (A) at the 50 watt-second stage of exercise.(ABSTRACT TRUNCATED AT 250 WORDS)