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.