Cor triatriatum with persistent levoatrial cardinal vein late presented as severe mitral stenosis.

Cor triatriatum is a rare congenital cardiac anomaly that usually becomes symptomatic in the first years of life. We present a 28-year-old pregnant female patient presented with shortness of breath, palpitations and decreased exercise tolerance. Transthoracic (TTE) and transesophageal (TEE) echocardiography showed cor triatriatum, features of severe mitral stenosis and atrial septal defect (ASD). The patient underwent successful surgical correction with an uneventful postoperative course.