AUTHOR=Molisana Michela , Selimi Adelina , Gizzi Germana , D’Agostino Simone , Ianni Umberto , Parato Vito Maurizio 

TITLE=Different mechanisms of mitral regurgitation in hypertrophic cardiomyopathy: A clinical case and literature review

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2022.1020054

DOI=10.3389/fcvm.2022.1020054

ISSN=2297-055X

ABSTRACT=Background. Abnormalities of the mitral valve (MV) apparatus are typical features of Hypertrophic Cardiomyopathy (HCM). These abnormalities include leaflet elongation, thick leaflets, displacement of papillary muscle, systolic anterior motion (SAM) of the mitral valve involving not only anterior mitral leaflet (AML) but also posterior mitral leaflet (PML). Mitral valve chordal rupture associated with HCM is a rare entity and predominantly involves PML. 
Case Summary. A 57-year-old lady with history of diabetes, dyslipidemia and a previous single episode of atrial fibrillation (treated with pharmacological cardioversion), presented to the Emergency Department (ED) for worsening dyspnea (NYHA class IV). A trans-thoracic echocardiogram (TTE) showed a significant, septal, asymmetric left ventricular hypertrophy (basal antero-septal wall diastolic thickness of 19 mm) with normal left ventricle (LV) systolic function. A SAM of AML was evident together with a left ventricular outflow tract (LVOT) gradient of 56 mmHg at rest, rising to 136 mmHg during Valsalva manoeuver. Additionally, there was evidence of moderate to severe mitral regurgitation (MR) with an anteriorly directed jet, not very typical of mitral regurgitation related to SAM. A 2D-3D trans-esophageal echocardiogram (2D-3D TEE) revealed a combined mitral regurgitation mechanism based on PML degenerative prolapse with P2-flail from ruptured chordae with related eccentric anteriorly directed regurgitant jet, together with a second regurgitant posteriorly directed jet, related to SAM of AML. The patient underwent mitral valve repair together with septal myectomy, with good final outcome. 
Conclusions. Pre-operative echocardiography (both TTE and 2D-3D TEE) is an essential tool in order to detect different mitral valve abnormalities in patients with HCM.  These type of patients should never be treated by septal reduction alone. Surgical mitral valve repair or replacement, together with septal myectomy, may be the preferred approach.