Partial Anomalous Pulmonary Venous Connection Draining into the Azygos System.

A 45-year-old woman with a history of a repaired atrial septal defect presented with progressive dyspnea and reduced exercise tolerance. Cardiac computed tomography revealed a right-sided partial anomalous pulmonary venous connection (PAPVC) draining into the azygos system, leading to surgical referral owing to persistent symptoms. PAPVC, a rare congenital heart defect often undiagnosed until adulthood, should be considered in patients with tricuspid regurgitation, pulmonary hypertension, or a right heart dilation of unknown etiology. Multimodal cardiac imaging is essential before invasive treatment in patients with congenital heart defects to identify associated anomalies and prevent complications from PAPVCs being overlooked.