Doppler Echocardiographic Evaluation of Hemodynamic Changes Following Infusion of Nitroglycerin in Cases With Patent Ductus Arteriosus and Pulmonary Hypertension

Acute hemodynamic effects of infused nitroglycerin on six patients with PDA whose pulmonary artery pressure was at systemic level were investigated by continuous Doppler echocardiography. Following infusion of nitroglycerin an increase of the flow from the aorta to the pulmonary artery during diastole was detected in two cases by Doppler echocardiography. In the other three patients there was no significant change in the Doppler flow spectrum after infusion. However in the last patient an increase of blood flow from the pulmonary artery to the aorta was recorded. The former two cases with change of flow were operated on successfully for PDA; the others were accepted as inoperable. This study showed that Doppler technique may be useful in the evaluation of pulmonary vascular reactivity to nitroglycerin. Using this method may help decide closure of PDA.