subject: Persistent ductus arteriosus clinical features and management [print this page] PERSISTENT DUCTUS ARTERIOSUS PERSISTENT DUCTUS ARTERIOSUS
Persistent ductus arteriosus (PDA) is a congenital abnormalitycaused by failure of the ductus arteriosus to closeand form the ligamentum arteriosum. The result is a shuntof blood from the aorta into the pulmonary circulation.The shunt is from the aorta just distal to the left subclavianartery, and so an increased flow occurs through the leftheart and pulmonary circulation but not the right heart.The ductus arteriosus remains patent for a variable timeafter birth, and failure to close can be associated withcongenital abnormalities other than PDA. The isolatedlesion is usually diagnosed in childhood from the presenceof a continuous or 'machinery murmur' at the upper leftsternal edge.
Clinical features
Overload of the left heart can lead to heart failure in older patients. The increased lung blood flow in infants can present with the consequences of increased pulmonary vascular resistance: extremely rarely, reversal of the flow through the ductus, with cyanotic blood passing to the distal aorta, occurs, producing clubbing of the toes butnot the fingers. Rarely, the ductus may be the site of endocarditis.
Investigation and management Diagnosis is based on the physical findings of the characteristic murmur, a collapsing pulse and a chest X-ray whichusually shows a prominent pulmonary conus and increasedlung blood flow.Echocardiography and Doppler ultrasound are extremelyuseful in demonstrating both the lesion and thevolume load on the left ventricle. Cardiac catheterizationwith aortography is not usually necessary in uncomplicatedcases, but it may be useful in differentiating the much less common aortopulmonary window, which requires muchmore complex surgery.Simple cases require ligation and transection of the PDA.
Persistent ductus arteriosus clinical features and management
