Pulsed wave Doppler interrogation in a patient with patent ductus arteriosus and systemic pulmonary artery pressure

In a patient with patent ductus arteriosus (PDA) and systemic pulmonary artery pressure (PAP), pulsed Doppler echocardiography (using the short axis view) shows systolic flow (arrows) is directed away from the pulmonary artery, across the PDA, and into the descending aorta. In diastole, flow reverses and is left to right, directed toward the pulmonary artery.