Impact of radiofrequency catheter ablation on echocardiographic and cardiopulmonary performance in patients with ventricular extrasystolic beats and suspected arrhythmia-induced cardiomyopathy

Frequent ventricular extrasystolic beats (VEBs) have been shown to induce dilated cardiomyopathy (DCM). There are limited data on cardiopulmonary performance after radiofrequency ablation (RFA) of VEBs. The aim of this study was to assess (1) the prevalence of arrhythmia-induced cardiomyopathy (AIC), and (2) echocardiographic and cardiopulmonary performance outcomes after RFA of isolated idiopathic VEBs. Two different cohorts were analyzed. (1) Among 9717 consecutive patients admitted to the cardiology department, the prevalence of DCM (4.3 %) and AIC (7 % of DCM) was established. (2) Consecutive patients admitted for RFA of VEBs were screened for DCM (decreased global contractility and ejection fraction ≤55 %). Cardiopulmonary exercise test (CPET) and echocardiography (TTE) were performed before and 4, 12, and 24 weeks after RFA. Other than AIC, possible causes of DCM were excluded. Suspected AIC was diagnosed in 21 of 197 (10.7 %) patients. The mean baseline number of VEBs 24-h Holter monitoring was 26,893 ± 13,883. The total number of beats was <120,000/24 h in all patients. The RFA was successful in 14 of 21 (66.6 %) patients. In 12 of 14 (85.7 %) subjects, improvement in CPET, TTE, and clinical presentation was noted. In seven patients in whom RFA was unsuccessful or not performed, no improvement in CPET was noted. In CPET two parameters significantly improved, VE/VCO₂ and PetCO₂, with a positive trend for VO₂max, VO₂AT, and VE/VO₂. In conclusion AIC constitutes 7 % of all DCM patients. Frequent VEBs cause DCM in about 10 % of patients referred for RFA. Successful RFA reverses symptoms of AIC, and improves echocardiographic and cardiopulmonary performance.