Hemodynamic consequences of afterload reduction in patients with valvular abnormalities

Ten patients with mitral insufficiency, eight patients with aortic insufficiency and eight patients with mitral stenosis were studied by right- and left-heart catheterization. Hemodynamic observations were made during a control period and during the infusion of phentolamine at a rate of 0.3 mg/min. The patients with mitral insufficiency and aortic insufficiency responded to phentolamine with a significant decline in the right and left ventricular filling pressures, pulmonary-artery mean pressure, peripheral resistance and arteriovenous oxygen difference. A significant increase in the cardiac index was seen in both groups. The patients with mitral stenosis did not show any hemodynamic improvement with the phentolamine infusion.