Transverse Pericardial Sinus Hematoma From Type A Aortic Dissection: A Diagnostic Challenge.

Ascending (type A) aortic dissection can rarely result in contained transverse pericardial sinus hematoma that compresses adjacent structures making diagnosis more challenging. We present a rare case of a 77-year-old man who presented with sudden-onset chest pain and was admitted for a presumed acute coronary syndrome. Coronary angiography did not show significant stenosis and ruled out acute coronary syndrome. Transthoracic echocardiogram showed extracardiac structure compressing on the left atrium; hence, we performed transesophageal echocardiogram which confirmed aortic dissection and revealed a hematoma in the transverse pericardial sinus. Intraoperatively, a large hematoma in the transverse pericardial sinus was extracted and revealed a posterior perforation of the ascending aorta that extended into the left atrium.