The effect of mitral valve surgery on ventricular arrhythmia in patients with bileaflet mitral valve prolapse

Abstract

Background: Bileaflet mitral valve prolapse (biMVP) is associated with frequent ventricular ectopy (VE) and malignant ventricular arrhythmia. We examined the effect of mitral valve (MV) surgery on VE burden in biMVP patients.

Methods: We included 32 consecutive patients undergoing MV surgery for mitral regurgitation secondary to biMVP between 1993 and 2012 at Mayo Clinic who had available pre- and post-operative Holter monitoring data. Characteristics of patients with a significant reduction in postoperative VE (group A, defined as >10% reduction in VE burden compared to baseline) were compared with the rest of study patients (group B).

Results: In the overall cohort, VE burden was unchanged after the surgery (41 interquartile range [16, 196] pre-surgery vs. 40 interquartile range [5186] beats/hour [bph] post-surgery; P = 0.34). However, in 17 patients (53.1%), VE burden decreased by at least 10% after the surgery. These patients (group A) were younger than the group B (59 ± 15 vs. 68 ± 7 years; P = 0.04). Other characteristics including pre- and postoperative left ventricular function and size were similar in both groups. Age <60 years was associated with a reduction in postoperative VE (odds ratio 5.8; 95% confidence interval, 1.1-44.7; P = 0.03). Furthermore, there was a graded relationship between age and odds of VE reduction with surgery (odds ratio 1.9; 95% confidence interval 1.04-4.3 per 10-year; P = 0.04).

Conclusions: MV surgery does not uniformly reduce VE burden in patients with biMVP. However, those patients who do have a reduction in VE burden are younger, perhaps suggesting that early surgical intervention could modify the underlying electrophysiologic substrate.

Keywords: Bileaflet mitral valve prolapse; Mitral valve surgery; Papillary ventricular arrhythmias; Sudden cardiac death; Ventricular arrhythmias; Ventricular ectopy.

Fig. 1

Electrocardiographic tracings identify site of origin of ventricular ectopy. (A) demonstrates ventricular ectopy from anterolateral papillary muscle with wide QRS complex and atypical right bundle branch block morphology (V1 lead) and inferior right axis. (B) presents posteromedial papillary muscle ventricular tachycardia with similar atypical right bundle branch block morphology but superior and left axis. (C) Right ventricular outflow tract ectopy with negative in V1 lead (left bundle branch bock morphology) and positive deflection in leads II, III, and aVF. In contrast to ectopy from left ventricular outflow tract, (D) which has positive reflection in V1 lead.