PAPVC

PAPVC stands for partial anomalous pulmonary venous connection, a congenital heart defect in which one or more pulmonary veins drain into the right atrium or systemic venous circulation rather than the left atrium. In most cases, the right upper pulmonary veins drain anomalously, commonly into the superior vena cava or right atrium, while the remaining pulmonary veins connect normally to the left atrium. PAPVC may occur alone or with an atrial septal defect.

Because some oxygenated blood returns to the right heart, PAPVC creates a left-to-right shunt. The shunt increases pulmonary blood flow and volume load on the right heart, which can lead to right atrial and right ventricular dilation, arrhythmias, and, if substantial, pulmonary hypertension. The clinical impact depends on the degree of drainage and coexistence with other defects such as ASD.

Most individuals are asymptomatic and diagnosed incidentally during imaging for unrelated reasons. When symptoms occur, they include exertional dyspnea, fatigue, palpitations, or recurrent chest infections. Diagnosis is usually made by echocardiography, with cardiac MRI or CT providing detailed anatomy of venous drainage. Cardiac catheterization may be used to assess hemodynamics and shunt size.

Management depends on shunt size and symptoms. Mild PAPVC with small shunts may be observed. Significant shunts or symptoms typically require surgical correction to redirect anomalous pulmonary veins to the left atrium and to repair or close a concomitant ASD. Outcomes after repair are generally favorable, though long-term prognosis depends on associated anomalies, postoperative right heart function, and arrhythmia risk. Regular follow-up is recommended.