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

Abstract

A56-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. 1 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 at www.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). 2 The diastolic interventricular septal 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. 2 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 avoid the possibility of a third cardiopulmonary bypass run in case of an insufficient repair. Postoperative 2D-TEE and Doppler assessment showed the typical echocardiographic signature of a bileaflet tilting disk valve with no residual regurgitation and no residual outflow tract gradient, and the patient had an unremarkable recovery.This case of complex MV disease in the context of SAM and HOCM highlights the potential difficulties in identifying the etiology of MR. Specifically, it demonstrates the diagnostic dilemma to discern the This article has supplementary material on the Web site:www.anesthesia-analgesia.org.

Hypertrophic cardiomyopathy part II - Anesthetic and surgical considerations

“…The measurement of mitral annular diameter, leaflet lengths, excessive length of PML, and the contribution of abnormal bands can be made out by 3D TEE. [53,54] The en-face view of the mitral valve in 3D aligned to the "surgeon's view" is helpful in identifying the prolapsed mitral scallop and demonstrating the complex anatomy of the mitral valve apparatus. [53] Post repair 3D TEE is helpful in assessing the adequacy of mitral valve repair and relief of LVOTO.…”

Three-dimensional Echocardiography Is Essential for Intraoperative Assessment of Mitral Regurgitation

“…53 By preoperatively quantifying the extent of the excess length, surface area, and billowing volume of the anterior and posterior leaflets, 3D TEE analysis helps identify patients at risk for developing systolic anterior motion. [54][55][56][57][58] Additionally, 3D TEE improves sizing of the mitral annuloplasty ring and may help identify possible interventional targets in patients with persistent mitral regurgitation from systolic anterior motion despite rerepair or myomectomy for left ventricular obstruction. Overall, 3D TEE has improved our understanding of the relationship between the mitral apparatus and adjacent structures such as the aortic root, which is important because distortion of the left ventricular outflow tract from rigid mitral annuloplasty rings can play a role in systolic anterior motion.…”

Evolving Role of Three-Dimensional Echocardiography in the Cardiac Surgical Patient

“…According to a recent study, 3D TEE provided an objective tool for predicting MV repair complexity involving bileaflet repair techniques, requiring multiple resections or patch augmentation, in patients with mitral regurgitation (MR), in which the most predictive models included three predictors: multisegment pathology, prolapsing height, and posterior leaflet angle [31]. RT-3D TEE (94 % accuracy) was superior to RT-2D TEE (71 % accuracy) in accurately identifying abnormal MV segments in patients undergoing MV surgery for MR when compared to the surgical finding as a gold standard, especially assessing the posterior leaflet [32]. In addition, 3D echocardiography provides more accurate and less variable measurement of the mitral valve area (MVA) in mitral stenosis compared to standard 2D-based measurements and shows the best agreement with invasive methods [33,34].…”