174: Premature ventricular beat-induced cardiomyopathy Characteristics and prognosis after radio-frequency ablation

Abstract

Frequent premature ventricular beats (PVB) may induce cardiomyopathy (CM) whose characteristics and underlying mechanisms are poorly known 38 patients (27 men, 57±16yo) with dilated CM associated with frequent isolated PVB suspected to be responsible the CM were ablated between 2005 and 2011. PVB were documented <1 year (n=11), between 1 and 5 years (n=8) and >5 years (n=10) before (unknown in 9). Ejection fraction (EF), left ventricular end-diastolic diameter (LVEDD) and NYHA class were compared before and after radio-frequency ablation. 16 pts with symptomatic PVB without CM serves as the control group Baseline EF was 39±1%, LVEDD was 61±7 mm and mean NYHA class was 1.9±0.8. PVB arose from the RV in 10 pts (RVOT in 7) and from the LV in 28 pts (LVOTt in 10 and coronary cusps in 10) Compared to the control group, daily PVB number was not different in pts with suspected VPB-induced CM (22000±12000 vs 20000±14000, p=ns), as was the presence of PVB left bundle branch pattern (24/38 vs 13/16, p=ns) and gender or age. Pts with suspected PVB-induced CM had more often right axis VPB (31/37 vs 10/16, p=0.08). History of PVB was shorter in controls. Origin of the PVB did not differ between groups RF ablation completely eliminated PVB in 26 pts (68%), partially in 4 and was inefficient in 8. During a follow up of 19±19 months, EF increased from 39±10 to 52±13% (p=0.003) while LVEDD decrease from 61±7 to 56±7 mm (p=0.002) leading to a decrease in NYHA class (1.9±0.8 to 1.4±0.6, p=0.02). Parameters related to the failure of ablation were an older age, a higher NYHA class and a LVOT location of the focus. Parameters related to the lack of reversal of CM in successful ablations, were an older age, a lower baseline EF, but not the length of PVB history. RF ablation of frequent PVB may lead to cure or significant improvement in 78% of pts with associated CM. Plausible mechanisms leading to a PVB-induced CM may associate a more longer history of PVB.