Accessory mitral valve tissue: an updated review of the literature

Abstract

Accessory mitral valve tissue (AMVT) is a rare congenital cardiac anomaly sometimes responsible for left ventricular outflow tract (LVOT) obstruction. It is diagnosed during both neonate-childhood and adult periods in patients usually symptomatic for dyspnoea, chest pain, palpitations, fatigue, or syncope. Nevertheless, AMVT is often an incidental finding. AMVT is most often associated with other cardiac and vascular congenital malformations, such as septal defects and transposition of the great arteries. Surgery is indicated only in cases of significant LVOT obstruction and in patients undergoing correction of other cardiac malformations or exploration of an intracardiac mass. Two-dimensional echocardiography, both transthoracic and transoesophageal, is considered the main imaging modality for AMVT diagnosis and patient follow-up. The recent introduction of three-dimensional echocardiography allows a more realistic characterization of this entity. We present three clinical cases in which AMVT was incidentally diagnosed during standard echocardiography and an updated review of the literature highlighting the usefulness of echocardiography for AMVT morphological and functional characterization as well as the most relevant clinical implications due to its discovery.

Accessory mitral valve mimicking aortic valve endocarditis as a cause of cerebrovascular accident

“…7 Most are diagnosed during childhood in association with other congenital heart defects. 5 An even more uncommon presentation is cerebrovascular accident (CVA). This obstruction occurs as a result of the mass effect of the AMV itself or due to the build-up of fibrous tissue from the turbulent flow created by the AMV.…”

Accessory Mitral Valve Leaflet Causing Severe Left Ventricular Outflow Tract Obstruction in a Preterm Neonate with a Partial Atrioventricular Septal Defect

“…3 Severe obstruction can present with substantial cardiovascular compromise in infancy, whereas less severe obstruction can go undetected into adulthood and be identified after detection of a murmur or presentation with dyspnea, fatigue, palpitations, chest pain, or syncope. [3][4][5] Most cases of AMVT are associated with other cardiac abnormalities. Manganaro and colleagues 4 identified 104 patients who were diagnosed with AMVT from 1963 to 2012.…”

“…[3][4][5] Most cases of AMVT are associated with other cardiac abnormalities. Manganaro and colleagues 4 identified 104 patients who were diagnosed with AMVT from 1963 to 2012. Most (86.6%) had signs of LVOT obstruction, and AMVT was most frequently associated with ventricular septal defect (19.2%), followed by subaortic membrane (9.6%), LV hypertrophy (8.6%), and transposition of the great arteries (7.7%).…”

“…Most (86.6%) had signs of LVOT obstruction, and AMVT was most frequently associated with ventricular septal defect (19.2%), followed by subaortic membrane (9.6%), LV hypertrophy (8.6%), and transposition of the great arteries (7.7%). 4 After reviewing 90 reports that detailed postoperative findings of LVOT obstruction involving AMVT, Prifti and colleagues 6 classified AMVT into 2 main types: fixed and mobile. Type I (fixed) can be nodular (type IA) or membranous (type IB), and type II (mobile) is pedunculated (type IIA) or leaflet-like (type IIB).…”

Acute Multiple Cerebral Infarction in a Patient with an Accessory Mitral Valve

“…An accessory mitral valve (AMV) is a rare congenital cardiac malformation that may be accompanied by other congenital heart diseases, including left ventricular outflow tract obstruction (1). We herein report the case of a patient with an AMV that was diagnosed after multiple cerebral infarctions.…”