[Effect of large doses of nifedipine on pulmonary hypertension in patients with recurrent pulmonary thromboembolism].

Thromboembolic pulmonary hypertension is an uncommon condition with poor prognosis. Vasodilators may be effective in some patients with that disease. The effect of nifedipine on hemodynamics was investigated in two patients with thromboembolic pulmonary hypertension treated with acenocoumarol. Nifedipine was administered in 20 mg doses hourly during right cardiac catheterization and was repeated after 1 hour until a decrease in systemic pressure occurred. Patients received 80 mg and 120 mg of nifedipine. Pulmonary artery pressures decreased in both cases. An increase of cardiac output and decrease of pulmonary vascular resistance were observed after 60-80 mg of nifedipine and continued to the end of the investigation. No effect on heart rate was observed. We suggest that high doses of nifedipine may be--in some patients--effective in reducing thromboembolic pulmonary hypertension.