347 ARRHYTHMIC MITRAL VALVE PROLAPSE AND MITRAL ANNULUS DISJUNCTION: WHEN PRIMARY PREVENTION IMPLANTATION OF ICD IS POSSIBLE?

Abstract

Abstract Mitral valve prolapse (MVP) is the most common valvular heart disease. Although MVP is generally considered benign, it can be associated with important complications, including sudden cardiac death (SCD). MVP is often related to mitral annular disjunction (MAD), a structural abnormality involving a distinct separation of the left atrium/mitral valve annulus and myocardium continuum. It is associated with an increased risk of arrhythmias and is an integral component of the arrhythmic MVP (AMVP) complex. Here we present a case report of a patient with MAD, Barlow's syndrome with bileaflet mitral prolapse and a history of recurrent non sustained ventricular tachycardia (NSVT) who underwent subcutaneous cardioverter defibrillator (ICD) implant in primary prevention. A 49 year old woman, with a history of moderate mitral regurgitation and posterior leaflet prolapse, was sent to our hospital by her cardiologist for the evidence on holter ecg of several tracts of non sustained ventricular arrhythmias. Transesophageal echocardiogram revealed the presence of moderate mitral regurgitation, bileaflet prolapse (mainly of the redundant posterior leaflet), dilation of the left atrium and positive Pickelhaube sign, suggestive of MAD. After few days was performed cardiac magnetic resonance imaging with evidence of mitral annulus disjunction associated with bileaflet prolapse and moderate mitral regurgitation. Delayed gadolinium enhanced (DGE) signal was found in the posterior basal wall. During hospitalization, she presented daily episodes of high frequency (>180 bpm) NSVT with right bundle block (RBBB) morphology and several premature ventricular complex. It was therefore decided to discharge the patient with Life Vest and five months later, after asking second opinion to an Italian high specialization center, we decided to place a subcutaneous ICD in primary prevention for the high arrhythmic risk of the patient. Arrhythmic mitral valve prolapse (AMVP) is an estimated cause of sudden cardiac death. It is known that patients with MVP and MAD have a high arrhythmic risk but there aren't trials that demonstrate the benefits of primary ICD implantation. The recent “EHRA expert consensus statement on arrhythmic mitral valve prolapse and mitral annular disjunction “ affirms that can be reasonable, primary ICD implant, in patients with AMVP, 1 high risk features (VT (hemodynamically tolerated), NSVT, unexplained syncope) and 2 or more phenotypic risk features (—T-wave inversion in the inferior leads, repetitive documented polymorphic PVCs, MAD phenotype, redundant MV leaflet, enlarged left atrium or ejection fraction≤50%, LGE). For this reason, our patient underwent subcoutanues ICD implant. Therefore, we believe that further studies, to develop guidelines for risk stratification of patients with evident MVP, would be beneficial in reducing the incidence of potentially fatal events in these patients.