[Acute dissection of the interatrial septum after re-replacement of the mitral valve--a case report].

A 64-year-old man who had received a Carpentier-Edward mitral valve replacement seven years earlier was seen with dyspnea on exertion. After re-replacement of the mitral valve with SJM prosthesis, the patient developed acute left-sided heart failure on the third postoperative day. Transesophageal echocardiography revealed abnormal lumen posterior to the left atrium with regurgitant flow from the left ventricle. Right and left atriotomy revealed dissection of the interatrial septum and after removal of the prosthesis, communication between the left ventricle and the dissected lumen was recognized. After closing the communicating orifice, SJM prosthesis was again sutured on the mitral annulus with sub-annular pledgets to reinforce the annular attachment. Excessive debridement of the annular tissue was thought to be a causative factor to develop the dissection of the interatrial septum after mitral valve replacement.