Hemodynamic effects of phentolamine in valvular abnormalities.

Seven patients with mitral insufficiency and seven patients with aortic insufficiency were studied by right and left heart catheterization. Hemodynamic observations were made during a control period and during the infusion of phentolamine. Significant declines in the pulmonary artery mean pressure, left ventricular end diastolic pressure, peripheral resistance, and arteriovenous oxygen difference were seen in both groups. The cardiac index increased significantly in the two groups. Phentolamine therapy produced favorable hemodynamic effects because of its vasodilating action as well as its positive inotropic effects.