Effect of Epicardial Catheter Ablation in the Vicinity of Coronary Artery in Pigs

Abstract

Objectives Transthoracic epicardial ablation is an emerging catheter ablation strategy being used clinically at increasing frequency. This study evaluates the effects of epicardial RF ablation in the vicinity of the coronary arteries (CA) in the pigs. Methods The study consisted of 14 pigs. A total of 20 lesions were created in the vicinity of CA by cooling on and 23 lesions were created in the detached of CA. RF power was 30 W for 60 seconds by cooling-on. We studied the biophysical characteristics of RF ablation lesions and the damage of CA. Results In the vicinity of CA, effective RF procedure was 77 % (15/20) by cooling-on and 40 % (4/10) by cooling-off (P=0.06). In the vicinity of CA, lesions created with cooling-on and cooling-off RF ablation were 4.4±1.6mm and 1.8±0.3 mm in depth (P<0.01). In the detached of CA, lesions created with cooling-on and cooling-off RF ablation were 7.1±2.0 mm and 4.1±1.1mm in depth (P<0.05). In the vicinity of CA, lesions created with cooling-on and cooling-off RF ablation were 173±57 mm3 and 68±22 mm3 in volume (P<0.01). In the detached of CA, lesions created with cooling-on and cooling-off RF ablation was 422±118 mm3 and 125±23 mm3 in volume. There was no damage to major epicardial arteries when the catheter tip was 5 mm away from the arteries. Conclusions Cooling-on RF ablation is useful and safety if ablation sites are 5 mm away from CA in the vicinity of CA