Abstract
BACKGROUND: Cyanotic congenital heart disease is not a rare entity, but fistula between the right pulmonary artery and the left atrium is an uncommon vascular anomaly. Although it is a real challenge to diagnose the case, detailed clinical evaluation and selective investigations are keys for diagnosis, and surgical intervention is still considered the best treatment option. CASE PRESENTATION: A 19 years old girl from the remote village of Nepal presented with the history of exercise intolerance associated with cyanosis and clubbing of the extremities. We diagnosed her as a case of right pulmonary artery to left atrial fistula, a rare variant of pulmonary arteriovenous malformation. She underwent successful surgical correction of the anomaly under cardiopulmonary bypass surgery. CONCLUSION: Direct communication between the right pulmonary artery and the left atrium is a rare cyanotic congenital heart disease, which is diagnosed late and often associated with the atrial septal defect. The best treatment available is surgical correction.