The effect of radiofrequency catheter ablation of frequent premature ventricular complexes and arrhythmia burden on left ventricular function

Background: Frequent premature ventricular complexes (PVC) are related to reversible tachycardia-induced cardiomyopathy. However, the role of arrhythmia burden on the outcome of the catheter ablation has not been fully recognised. Aim: The aim of this study was to assess the effect of catheter ablation and PVC burden in patients with and without structural heart disease (SHD) on left ventricular ejection fraction (LVEF). Methods: Transthoracic echocardiography was done before and six months after radiofrequency catheter ablation in 109 consecutive patients (61 men, age 55 +/- 17 years) with frequent PVCs. Sixty-five (59.6%) patients had underlying SHD. Results: The catheter ablation procedure was successful in 93 (85.3%) patients. Baseline PVC burden was higher in patients with SHD (22,267 +/- 12,934) compared to those without concomitant SHD (15,546 +/- 7888), p = 0.005. Nevertheless, patients with LVEF <= 50% at baseline presented greater LVEF recovery (from 44% to 56%) than those with LVEF > 50% at baseline after catheter ablation. In both groups, the LVEF improved (p < 0.001); however, no difference was observed between patients with SHD (5.7% +/- 1.37%) and without (4.6% +/- 0.96%) SHD; p = 0.89. PVC burden was higher in patients with (24,350 +/- 2776 PVC/day) compared to those without (17,588 +/- 1970 PVC/day) improvement of LVEF. In multivariate regression analysis PVC burden > 20,000/day (but not age, p = 0.95; gender, p = 0.89; presence of SHD, p = 0.53; QRS complex width of the treated PVC, p = 0.21, LVEF before ablation, p = 0.19; and site of origin, p = 47) predicted improvement in LVEF after successful catheter ablation (odds ratio: 3.53; 95% confidence interval: 1.15-10.75; p = 0.023). Conclusions: Catheter ablation of frequent PVCs improves left ventricular function in multivariate analysis predicted improvement of LVEF within six months after the successful catheter ablation procedure in patients with PVC burden exceeding 20,000/24 h.