Hydralazine in Pulmonary Hypertension

To the Editor: The symptomatic fall in blood pressure with one ensuing death after administration of hydralazine to 13 patients with pulmonary hypertension recently described by Packer et al.¹ is alarming. Only some patients with severe pulmonary hypertension still have a lung bed capable of dilatation.² In those who do not, cardiac output is limited by high pulmonary vascular resistance,^2,3 and the only effect of an unselective vasodilator is to cause systemic hypotension. The adverse results obtained with hydralazine strongly argue for an initial assessment of the potential reversibility of high pulmonary vascular resistance, using either a selective pulmonary.