Mitral Valve Prolapse and Systolic Anterior Motion Illustrated by Real Time Three-Dimensional Transesophageal Echocardiography

摘要

A 56-yr-old man presented with increasing dyspnea with mild to moderate exercise. Transthoracic echocardiography demonstrated hypertrophic obstructive cardiomyopathy (HOCM), systolic anterior motion (SAM) of the anterior mitral valve (MV) leaflet, with a left ventricular outflow tract (LVOT) peak velocity of 4.2 m/s at rest (obtained from an apical window) and moderate to severe mitral regurgitation (MR). In agreement with current consensus guidelines, the patient was scheduled for left ventricular surgical septal myectomy. The intraoperative two-dimensional transesophageal echocardiography (2D-TEE) before cardiopulmonary bypass confirmed the diagnosis of marked HOCM, SAM, and severe MR and identified a prolapse of the P2 scallop of the posterior mitral leaflet (PML) using standard midesophageal (ME) views (Video Clip 1; please see video clip available atwww.anesthesia-analgesia.org). Severe MR was confirmed by both, a vena contracta of 7 mm and systolic reversal during Doppler interrogation of the pulmonary venous flow. Of note, the MR jet peaked in mid and late systole based on color flow Doppler. The MR jet originated anteriorly and was then directed centrally and slightly posteriorly, suggesting a significant role of SAM rather than PML prolapse alone in the etiology of MR (Video Clip 1). The diastolic interventricularseptal thickness measured 26 mm in the ME long axis view. M-mode assessment of the aortic valve in the ME aortic valve long axis view confirmed dynamic outflow tract obstruction, as leaflets opened initially, but closed in mid systole. Therefore, the patient underwent left ventricular septal myectomy aiming to alleviate LVOT obstruction and SAM and ultimately to improve the degree of MR. However, 2D-TEE assessment after myectomy demonstrated unaltered MR and persistent SAM of the MV, prompting the surgeon to replace the MV with a low profile mitral prosthesis (29 mm mechanical St. Jude prosthesis). Immediate MV replacement, rather than an attempt to repair the MV, was selected to avoidthe possibility of a third cardiopulmonary bypass run in case of an insufficient repair. Postoperative 2D-TEE and Doppler assessment showed the typical echocardiographicsignature of a bileaflet tilting disk valve with no residual regurgitation and no residual outflow tract gradient, and the patient had an unremarkable recovery.