Abstract
A BSTRACT Atrial septal defects (ASDs) are among the most common congenital heart defects diagnosed in adults. They may remain asymptomatic for many years; however, the physiological and hemodynamic changes associated with pregnancy and the postpartum period can trigger clinical manifestations. We describe a 23-year-old postpartum patient in whom severe pulmonary hypertension led to the diagnosis of a previously unrecognized ASD. Transthoracic contrast echocardiography (bubble test) revealed bidirectional right-to-left shunting. Despite the absence of right heart catheterization, prompt detection allowed timely management and planning for definitive surgical correction. This case highlights the importance of maintaining a high index of suspicion for ASDs in postpartum patients presenting with acute cardiopulmonary symptoms.