Vasodilator Therapy for Acute Heart Failure

Haemodynamic comparison of three vasodilation regimens intravenous (i.v.) hydralazine and isosorbide dinitrate (ISDN) combined, i.v. doxazosin, and i.v. enalaprilat was undertaken in 36 patients with acute left ventricular (LV) failure due to recent myocardial infarction. Each regimen achieved similar reductions in pulmonary artery occluded pressure (PAOP, preload) and systemic arterial pressures (afterload), with increased cardiac and stroke volume (SV) indexes (p less than 0.01). Only the hydralazine and isosorbide combination induced resting tachycardia. Balanced vasodilatation after selective alpha-adrenoceptor blockade (doxazosin) and angiotensin-converting enzyme (ACE) inhibition (enalaprilat) without increase in heart rate (HR) suggests that these therapies may have definite haemodynamic advantages over the hydralazine/ISDN combination.