Effects of Aminophylline on the Pulmonary Circulation and Left Ventricular Performance in Patients with Valvular Heart Disease

Abstract

The effects of aminophylline given intravenously on the pulmonary circulation and left ventricular performance were studied during combined right and transseptal left heart catheterization in 32 patients with mitral and aortic valvular disease. We recorded complete data on the changes of the pulmonary vascular distending pressure (P_D) and the pulmonary blood volume (PBV) before and during aminophylline infusion in 28 patients. In 19 patients a fall in the P_D was associated with a rise in the PBV. In eight patients a decline in the P_D was accompanied by a fall (five patients) or no change (three patients) in the PBV. In a single case, both P_D and the PBV rose. In the majority of cases, observation of decrease in P_D and a discordant rise in PBV is new evidence suggestive of a direct active vasodilating effect of aminophylline on the pulmonary vasculature. Although the cardiac index was unaffected, a positive inotropic effect on the myocardium was documented by a decrease in left ventricular end-diastolic pressure accompanied by an increase in the maximum rate of ventricular pressure rise (LV dp/dt). These findings contrast with those in certain patients with heart failure of nonvalvular origin in whom increases in cardiac index are usually prominent. The salutory effect of aminophylline in acute pulmonary edema is thought to be due to synergistic effects on the systemic circulation, pulmonary circulation, and left ventricular function, all of which tend to produce a fall in P_D.