Verapamil and pulmonary hypertension.

We report on the effect of verapamil in 12 patients suffering from pulmonary hypertension. The drug caused a slight, but statistically significant decrease in mean pulmonary artery pressure and in the work performance by the right ventricle. The mean pressure of the right atrium, the end-diastolic pressure of the right ventricle, the pulmonary arteriolar resistance, the cardiac index and the stroke volume were not significantly changed, however, and there was a wide spread of the values observed. In some patients the drug exerted a marked negative inotropic effect, with a concomitant increase in the pulmonary arteriolar resistance.