Patent ductus arteriosus (PDA) is a congenital heart defect in which the ductus arteriosus — a blood vessel that connects the pulmonary artery to the aorta during fetal life to bypass the non-functioning lungs — fails to close after birth as it normally should. When this vessel remains open, it allows oxygenated blood from the aorta to flow backward into the pulmonary artery, increasing blood flow to the lungs and adding workload to the heart. On echocardiography, a PDA appears as a small vessel between the aorta and pulmonary artery with continuous turbulent flow detectable on color and spectral Doppler. PDA is particularly common in premature infants, and echocardiography is the standard tool for diagnosing, assessing severity, and monitoring the response to treatment.
Sonography Term