Partial Anomalous Pulmonary Venous Return as Rare Cause of Right Ventricular Dilation: A Retrospective Analysis

Introduction: Partial anomalous pulmonary venous return (PAPVR) is an uncommon cause of right ventricular dilation. It may be difficult to identify and often remains undiagnosed. Methods: We reviewed the database of the Cardiac Magnetic Resonance (CMR) Laboratory of Niguarda Hospital, in order to identify the cases of PAPVR between 2008 and 2014. Results: On a total number of 7832 CMR scans, we identified 24 patients with PAPVR (14 male, age 41 ± 18 y) corresponding to 0.31% of the total population. Only 30% of patients had been referred for known or suspected PAPVR, 33% of patients had been referred for suspected right ventricular arrhythmogenic dysplasia and 37% had been referred for other cardiac disease. PAPVR involved mainly the right pulmonary veins (18 patients, 75%) and in 62% of our cases was associated with an atrial septal defect. Eight patients underwent corrective surgery in our institution, which confirmed and successfully repaired the anomalies. Conclusions: PAPVR is a rare congenital cardiac pathology which should be suspected in case of unexplained right chambers enlargement. CMR imaging allows an accurate anatomic and functional definition of this pathology and associated abnormalities. Early correction has an excellent prognosis and prevents long term complications like pulmonary hypertension, right ventricular failure and atrial fibrillation.