C  2006, the Authors Journal compilation C  2006, Blackwell Publishing, Inc. Left Atrial Septal Ventricularization Complicated by Paravalvular Leak, After Reoperation for Mitral Valve Replacement Amgad N. Makaryus, M.D., ∗ John N. Makaryus, B.A., ∗ Alan Hartman, M.D.,† and Smadar Kort, M.D.‡ ∗ Division of Cardiology and †Cardiothoracic Surgery, North Shore University Hospital, Manhasset, New York, and ‡Division of Cardiology, Stony Brook University Hospital, Stony Brook, New York Case Summary A 42-year-old woman with a history of rheumatic heart disease and hepatitis B pre- sented with dizziness and failure to thrive. Ten years prior to admission, the patient underwent mitral valve replacement with St. Jude pros- thesis, and a redo-replacement with another St. Jude mitral prosthesis less than 1 year prior to this hospitalization in the Dominican Republic. Since the second surgery, the patient started having worsening symptoms of nausea, vom- iting, and weakness. The patient appeared cachectic with the presence of bibasilar rales, ascites, and lower extremity pitting edema on physical exam. Cardiac examination revealed a III/VI holosystolic murmur heard best at the apex with radiation to the left axilla and evidence of congestive heart failure. She was referred for echocardiography, which demon- strated an abnormal mechanical valve prosthe- sis. The anterior aspect of the prosthesis was displaced superiorly 4 cm above the mitral an- nulus into the left atrium (LA). A small cham- ber was then created by the ventricularized por- tion of the interatrial septum and the prosthesis (Fig. 1). This chamber communicated with the LA resulting in a severe paravalvular leak (Fig. 2) and with the right atrium (RA) resulting in a left ventricular to RA shunt. In addition, se- vere tricuspid regurgitation and moderate pul- monary hypertension were also noted. Left ven- tricular systolic function was normal. These findings were confirmed on transesophageal Address for correspondence and reprint requests: Smadar Kort, M.D., F.A.C.C., F.A.S.E., State University of New York, Stony Brook University Hospital, Health Sciences Center 16-080, Stony Brook, NY 11794-8171. Fax: 631-444-1054; E-mail: smadar.kort@stonybrook.edu;skort123@pol.net echocardiography (Fig. 3). Cardiac angiography revealed no obstructive coronary disease. The patient was then referred for cardiotho- racic surgery for an abnormal mitral valve pros- thesis. During surgery, the communication be- tween the RA and the left ventricle through the ventricularized portion of the interatrial sep- tum was revealed. This portion of the septum was resected and the communication closed. The paravalvular leak was repaired with su- tures. The patient’s postoperative course was complicated by bradyarrhythmias, sepsis, ane- mia, severe malnutrition, and prolonged in- tubation with eventual tracheostomy. She ul- timately recovered and was discharged home after a protracted hospital stay. Follow-up echocardiography revealed an intact mitral valve prosthesis. Discussion Cardiac valve replacement with various types of prostheses has been recognized to result in both early and late complications. Among these complications, paravalvular leaks, al- though found to have a low incidence, have been noted to occur. Our case depicts the for- mation of a false chamber which communi- cated with the RA resulting in a left ventric- ular to RA shunt, and also with the LA re- sulting in a severe paravalvular leak. One ex- planation for the formation of such a chamber is dissection of the interatrial septum. Prior reports 1–3 have documented interatrial septal rupture following mitral valve replacement. In all of these cases, the echocardiogram, specifi- cally the transesophageal echocardiogram, was instrumental in the identification of the par- avalvular leak and documentation of the inter- atrial dissection. The reason for the dissection in these cases was generally noted to be the 522 ECHOCARDIOGRAPHY: A Jrnl. of CV Ultrasound & Allied Tech. Vol. 23, No. 6, 2006