Left ventricular hypertrophy and ventricular ectopy in mitral valve prolapse

Sudden deaths ascribed to mitral valve prolapse (MVP) have increased ventricular mass on autopsy. It is unknown if left ventricular hypertrophy (LVH) is a risk factor for ventricular arrhythmia in MVP.

We studied all 629 patients aged 18-90 years with MVP on echocardiography between 2016 and 19 at our institution. Echocardiograms were reviewed for LVH, ventricular size and function, and valvular pathology. Complex or frequent ventricular ectopy (cfVE) was defined as ≥ 2 premature ventricular complexes (PVC) on a 10-s ECG or > 1 % PVC burden or non-sustained ventricular tachycardia on ambulatory ECG. Multivariable logistic regression and cox proportional hazards regression were used to assess the relationships between LVH, mitral valve structural features, and cfVE in MVP.

LVH was present in 141 (22.4 %) patients. Of those with LVH, 44 (31.2 %) had cfVE compared to 87 (17.8 %) without LVH (p = 0.001). Independent predictors of cfVE were mitral annular disjunction (OR [95 % CI] 2.34 [1.54-3.56]), bileaflet prolapse (1.78 [1.19-2.66]), heart failure (1.79 [1.15-2.79]), lower ejection fraction (0.18 [0.04-0.83]), coronary artery disease (1.58 [1.04-2.39]), and T-wave inversion (1.51 [1.03-2.22]). However, LVH was not independently associated with cfVE (1.22 [0.82-1.83], p = 0.32).

Left ventricular hypertrophy is not an independent risk factor for ventricular arrhythmia in MVP. Ventricular arrhythmogenesis in MVP is predominantly determined by mitral morphological factors and heart failure. Further work is required to better understand the predisposition to sudden death of patients with MVP and increased ventricular mass.