Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 10-09: Patent Ductus Arteriosus + Key Features Download Section PDF Listen +++ ++ Embryonic ductus arteriosus fails to close, resulting in continuous (systolic and diastolic) shunt of blood from aorta to left pulmonary artery (PA) Usually located near the origin of the left subclavian artery Effect of persistent left-to-right shunt on PA pressure depends on size of ductus Small or moderate size patent ductus usually asymptomatic until middle age Large patent ductus causes pulmonary hypertension, and Eisenmenger physiology may result + Clinical Findings Download Section PDF Listen +++ ++ Symptoms only if left ventricular (LV) failure or pulmonary hypertension develops Heart size is typically normal or slightly enlarged Hyperdynamic apical impulse Wide pulse pressure and low diastolic pressure Continuous rough "machinery" murmur Thrill is common in upper right chest Advanced disease: cyanotic lower legs (especially toes) in contrast to normally pink fingers due to reversal of shunt when pulmonary hypertension is present + Diagnosis Download Section PDF Listen +++ ++ ECG: Normal tracing or LV hypertrophy Chest radiograph Normal-sized heart or LV and left atrial enlargement Prominent PA, aorta, and left atrium Echocardiography/Doppler Can determine LV, RV, and atrial dimensions Color flow Doppler allows visualization of the high velocity shunt jet into the proximal left PA However, lesion is best visualized by MRI, CT, or contrast angiography Cardiac catheterization can assess ductus and shunt size and direction Invasive hemodynamic testing defines pulmonary pressures Vasodilatory testing can be performed to see if the pulmonary hypertension is reactive + Treatment Download Section PDF Listen +++ ++ Large shunts: high mortality early in life Smaller shunts: compatible with long-term survival; heart failure most common complication Antibiotic prophylaxis for dental procedures recommended to prevent endocarditis Surgical ligation or, if ductus size is small enough, transcatheter closure using occluder devices Ductus closure is usually attempted unless pulmonary hypertension and right-to-left shunting is present Patients with an Eisenmenger physiology (shunt reversal) may benefit from vasodilator therapy To monitor patients with shunt reversal, serial assessment of toe oxygen saturation can be used as a marker of improvement in the right-to-left shunt On rare occasions, the ductus may become aneurysmal and require surgical repair