Effects of oral hydralazine on rest and exercise hemodynamics in patients with aortic or mitral regurgitation and left ventricular dysfunction.

The hemodynamic effects of afterload reduction were studied at rest and during two levels of upright exercise in patients with aortic or mitral regurgitation and left ventricular dysfunction. Eleven patients underwent invasive hemodynamic monitoring before and after 50-70 mg of oral hydralazine was given ever 6 h for 48 h. At rest, heart rate and mean arterial pressure after hydralazine were unchanged from control. During exercise, there was no significant change in heart rate, but mean arterial pressure fell significantly during the first level of exercise. Systemic vascular resistance was elevated before hydralazine and was significantly reduced after treatment at both exercise levels. After hydralazine, the resting oxygen consumption was significantly elevated at rest but was unchanged during exercise, the arteriovenous oxygen difference was significantly narrowed at both rest and exercise, and the pulmonary capillary wedge pressure was also significantly lower at both rest and exercise. In this select group of patients who are not candidates for surgical valve replacement, chronic afterload reduction with oral hydralazine may result in increased cardiac performance, decreased pulmonary congestion, reduced myocardial oxygen demands, and improvement in resting and/or exertional symptoms.