Arrhythmogenic Mitral Valve Prolapse

Abstract

Mitral valve prolapse (MVP) is a common condition present in 1-3% of the population. There has been evidence that a subset of MVP patients is at higher risk of sudden cardiac death. The arrhythmogenic mechanism is related to fibrotic changes in the papillary muscles caused by the prolapsing valve. ECG features include ST-segment depression, T wave inversion or biphasic T waves in inferior leads, and premature ventricular contractions arising from the papillary muscles and the fascicular system. Echocardiography can identify MVP and mitral annular disjunction, a feature that has significant negative prognostic value in MVP. Cardiac MRI is indicated for identifying fibrosis. Patients with high-risk features should be referred for further evaluation. Catheter ablation and mitral valve repair might reduce the risk of malignant arrhythmia. MVP patients with high-risk features and clinically documented ventricular arrhythmia may also be considered for an ICD.

Keywords: Arrhythmia; echocardiography; mitral annular disjunction; mitral valve prolapse; papillary muscle fibrosis; premature ventricular contractions; sudden cardiac death.

Figure 1:. 12-Lead ECG with Premature Ventricular Contractions Arising Either from the Mitral Annulus or from the Posterior Papillary Muscle

Figure 2:. Bileaflet Mitral Valve Prolapse with Flail (Black Arrow) Posterior Lateral Scallop Imaged with 3D Echocardiography

Figure 3:. Mitral Annular Disjunction Characterised by the Detachment of the Roots of the Posterior Part of the Mitral Annulus Under P1 and P2 Segments

Figure 4:. Presence of Mitral Annular Disjunction at the Four-chamber View on Transthoracic Echocardiography

Figure 5:. Cardiac MRI with Evidence of Mitral Annular Disjunction (Yellow Line)