Short- and long-term effects of hydralazine and combined hydralazine-prenalterol therapy in severe chronic congestive heart failure.

The hemodynamic benefits of combined administration of prenalterol (P) with hydralazine (H) were evaluated in ten patients with severe chronic heart failure. Single administration of 100 mg H increased cardiac index (CI) from 2.3 to 3.0 l/min/m2, whereas pulmonary capillary wedge pressure (PWC) remained unchanged. After 3--4 weeks of treatment with 200 mg H hemodynamic improvementt was maintained (CI: 2.9 l/min/m2). Additional administration of P caused further augmentation of CI (3.3 l/min/m2). After long-term treatment with the combination of H and P sustained augmentation of CI (3.2 l/min/m2), and, furthermore, a slight but significant decrease of PCW were observed (p less than 0.05 vs. chronic single H-therapy). Five patients were able to perform exercise testing; H improved maximal exercise capacity and exercise hemodynamics in three patients. Further improvemen was observed after combined treatment (H + P) in three of five patients. It is concluded, the prenalterol may enhance the effectiveness of hydralazine therapy in congestive heart failure by providing concomitantly the principal actions of the vasodilator and positive inotropic agent used separately. Furthermore, the results indicate that oral long-term administration of hydralazine and prenalterol can produce sustained beneficial improvement.