[Orally active vasodilators in the management of chronic treatment-resistant cardiac failure (author's transl)].

The acute haemodynamic effects of 40 mg isosorbide dinitrate (10 subjects), 4 mg prazosin (20 subjects) and 50 mg dihydralazine (8 subjects) were compared in 24 patients with the clinical picture of chronic therapy-resistant cardiac failure (NY Heart Association stages III-IV). There was a fall in left-ventricular filling pressure of about 15% and right-atrial mean pressure of 21 and 24%, respectively, with isosorbide dinitrate and prazosin, while there was no change with dihydralazine. Cardiac output rose by 23% with dihydralazine and 20% with prazosin, but remained unchanged with isosorbide dinitrate. These data indicate that a reduction in pulmonary and systemic-venous congestion due to chronic decompensated cardiac failure can be achieved with isosorbide dinitrate and prazosin, while cardiac output can be improved only with prazosin and dihydralazine.