Role of digoxin in right ventricular failure due to chronic cor pulmonale.

The effect of digoxin in the treatment of decompensated chronic cor pulmonale was investigated in a randomized double-blind, cross-over, placebo-controlled trial. A total of 34 successive patients with evident right heart failure were included in the study. The mean maintenance daily dose of digoxin was 0.30 +/- 0.03 mg with the mean serum level of 1.7 +/- 0.7 nmol/L. The severity of heart failure was assessed according to a clinicoradiographic scoring system (Heart Failure Score). The heart failure worsened during the placebo-period in eight (23.5%) patients (four with atrial fibrillation, two with a third heart sound (S3), one with a cardiothoracic ratio of more than 0.5 and one with sinus rhythm). By regression analysis, the heart failure significantly worsened only in the subgroup of patients with atrial fibrillation. Digoxin was successfully (without worsening of the heart failure) discontinued in 26 (76.5%) patients. No significant improvement was observed in the patients with S3 gallop. It was concluded that digoxin had no beneficial effect in chronic cor pulmonale patients with heart failure, except in those with atrial fibrillation.