Left ventricular mechanical dispersion predicts arrhythmic risk in mitral valve prolapse

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Electrophysiology

Background:

• Bileaflet mitral valve prolapse (MVP) is associated with myocardial fibrosis, increasing risk of ventricular arrhythmia and sudden cardiac arrest.
• Left ventricular (LV) mechanical dispersion, assessed by speckle-tracking echocardiography (STE), reflects heterogeneous ventricular contraction and correlates with myocardial fibrosis.

Purpose of the Study:

• To determine if LV mechanical dispersion can identify patients with MVP who are at higher risk for arrhythmias.
• To investigate the association between mechanical dispersion and arrhythmic complications in MVP patients.

Main Methods:

• Speckle-tracking echocardiography (STE) was used to measure global longitudinal strain (GLS) and LV mechanical dispersion.
• Mechanical dispersion was calculated as the standard deviation of the time to peak strain across 18 LV segments.
• The study included arrhythmic MVP (A-MVP), non-arrhythmic MVP (NA-MVP), and control groups.

Main Results:

• MVP patients exhibited significantly higher mechanical dispersion than controls (52 vs 42 ms, p=0.005), despite similar LV ejection fraction and GLS.
• Arrhythmic MVP (A-MVP) patients showed greater mechanical dispersion compared to non-arrhythmic MVP (NA-MVP) patients (59 vs 43 ms, p=0.0002).
• Mechanical dispersion was the sole significant predictor of arrhythmic risk in multivariate analysis (OR 1.1, p=0.006).

Conclusions:

• STE-derived mechanical dispersion is a valuable tool for identifying MVP patients at elevated risk of ventricular arrhythmias.
• This finding aids in risk stratification and management of MVP patients prone to cardiac events.