Coronary Sinus Atrial Septal Defect

Coronary sinus atrial septal defect (ASD) is a rare interatrial shunt that is commonly associated with a persistent left superior vena cava (PLSVC) and constitute less than 1 % of cases of ASDs. It is characterized by the absence of at least a portion of the common wall that separates the coronary sinus and left atrium. Isolated defects are associated with low rate of morbidity and mortality..A 16-year old girl was diagnosed with features of an atrial septal defect (ASD) by transthoracic echocardiography and the absence of PLSVC (persistent left superior vena cava) connection to coronary sinus was confirmed by saline contrast echocardiography ("bubble study").The cause of the dilated coronary sinus was due to total anomalous pulmonary venous connection.