Abstract 20821: Radiofrequency Ablation of Premature Ventricular Ectopy Can Improve Left Ventricular Function and Heart Failure Class in Non-Responders of Cardiac Resynchronization Therapy
Objectives: Cardiac Resynchronization therapy (CRT) is an effective therapeutic strategy in patients who do not respond to conventional heart failure therapy. Approximately 30–40% of patients do not respond to CRT and the underlying reasons for the lack of response are poorly understood. Frequent premature ventricular contraction (PVC) is not uncommon in these patients. We evaluated whether radiofrequency ablation (RFA) of the PVC focus would improve left ventricular ejection fraction (LVEF).
Methods: We prospectively studied 847 eligible patients who had CRT for refractory CHF between 2008–2010 at 4 participating institutions. Response to CRT was defined as at least 5% improvement in EF or 15% improvement in LV volumes. Of these, 203 (24%) patients did not respond to CRT. Frequent PVC (>10,000/24 hours) were noted in 52 nonresponders, who underwent RFA using 3D-electroanatomic mapping. Successful ablation was defined as <1000 PVCs/24 hour period. Follow-up echo was done after 6 months to assess LVEF and LV volumes. Pre and post-RFA NYHA functional class was also assessed.
Results: Twenty-six percent (52/203) of CRT nonresponders underwent RFA (68% males, age 65±12 years). Nonischemic cardiomyopathy was present in 58%. Intracardiac echo and 3D mapping guided RFA of the PVC focus was attempted using a 3.5 mm Biosense Webster open irrigated catheter. Distribution of site of origin is as follows — Submitral annular foci in 19, RVOT in 12, LVOT 3, aortic cusp 3, aortomitral continuity in 3, His purkinje in 4, papillary muscle in 2 and around the scar border in 6 patients. Epicardial focus was seen in 6% of cases. More than one focus was seen in 10%. Acute success was seen in 96%. At 3 months 84% had successful ablation with 64% free of PVCs. Acute success was achieved in 96%. At 3 months, 84% had successful ablation with 64% free of PVCs. Compared with baseline values, significant improvements were noted in LVEF (35±6 % vs. 28±4%), LVESD (5.1±0.4 mm vs. 5.7±0.6 mm), LVEDD (7.4±0.5mm vs. 6.4±0.3mm) and NYHA class (3.2 vs. 2.4) in patients with ≥20,000 PVCs (35/52, 67%).
Conclusions: Frequent monomorphic PVC is not an uncommon cause of no response to CRT. RFA of the ectopic focus is effective in improving response to CRT in patients with excessive PVC burden (≥ 20,000/24 hour).
- © 2010 by American Heart Association, Inc.