Provocation of myocardial ischemic events during initiation of vasodilator therapy for severe chronic heart failure. Clinical and hemodynamic evaluation of 52 consecutive patients with ischemie cardiomyopathy

Although hydralazine provokes myocardial ischemie events in hypertensive patients not in heart failure by producing reflex tachycardia, the frequency of and mechanisms underlying ischemie events when this drug is administered as a vasodilator agent to patients with heart failure is unknown. The responses to hydralazine in 52 consecutive patients with severe chronic heart failure secondary to coronary artery disease were reviewed. Twelve patients (23 percent) had 16 ischemie events during the initial administration of hydralazine (angina at rest in 12 and myocardial infarction in 4); these generally occurred in the absence of significant tachycardia and hypotension. Thirty-five of the 52 patients received nitroprusside (8 of whom had ischemie events with hydralazine), but this drug provoked ischemia in only 1 of the 35 although it resulted in greater decreases in systemic arterial pressure than occurred with hydralazine. In patients with an ischemie event only with hydralazine, left ventricular filling pressure decreased 14.6 mm Hg with nitroprusside but only 3.9 mm Hg with hydralazine (probability [p] < 0.01). Provocation of ischemia with hydralazine may therefore be due to the relative preservation of elevated left ventricular preload with this drug, since ischemie events are not common with nitroprusside despite greater decreases in systemic pressures.