Do i.v. doxazosin or i.v. enalaprilat provide haemodynamic advantages over i.v. hydralazine/ISDN in patients with acute LV failure due to recent myocardial infarction?
Intravenous doxazosin and enalaprilat provide balanced vasodilatation without inducing resting tachycardia, offering potential haemodynamic advantages over hydralazine/ISDN in acute heart failure post-MI.
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.
Verma et al. (1992) studied this question.