Hemodynamics in Patent Ductus Arteriosus Without a Murmur

Abstract

The clinical and hemodynamic features are described in a 7½-year-old boy who had a patent ductus arteriosus and pulmonary hypertension without a murmur. Values for oxygen saturation of the blood and dye-dilution curves demonstrated that the flow through the ductus was mainly from pulmonary artery to aorta. This was reversed when the patient breathed 99.6 per cent oxygen. Blood shunted from right to left through the ductus could be detected at the right radial artery. Thus retrograde movement of blood occurred in the aortic arch. Clamping of the ductus caused an increase in pulmonary arterial pressure, a decrease in systemic arterial pressure, an increase in arterial oxygen saturation and a change in the arterial dye-dilution curve toward normal. Division of the ductus was followed by clinical improvement.