The comparison of epicardial focused ultrasound CPV ablation and BOX ablation: results from experimental acute atrial fibrillation model

Abstract

Background Focused ultrasound ablation research commences in cardiology, and we seek to compare efficacy of focused ultrasound circumferential pulmonary veins ablation (CPVa) and BOX ablation (BOXa) in acute atrial fibrillation (AF) model. Method Twenty mongrel dogs were divided into either CVPa or BOXa groups. CPV or BOX focused ultrasonic ablation (type: CZB, High Intensity Focused Ultrasound (HIFU), China) was performed in corresponding group when acute AF models established. Left atrial effective refractory period (LAERP), inducibility, and induced AF lasting time were evaluated preand post-ablation in both groups. The histological observation was performed after ablation procedures. Results The LAERP after AF model establishment was significantly shorter than that before establishment (102+10 ms vs 140+10 ms, p<0.01, in CPVa group; 105+8 ms vs 139+11 ms, p<0.01, in BOXa group). The AF inducibility after ablation was significantly lower than that before ablation in two groups (98+4% vs 28+10%, p<0.01, in CPVa group; 97+4% vs 14+7%, p<0.01, in BOXa group), and the induced AF lasting time after ablation was significantly shorter than that before ablation in both groups (233+40 s vs 70+29 s, p<0.01, in CPVa group; 240+41 s vs 34+22 s, p<0.01, in BOXa group). During two groups comparison, AF Inducibility and induce AF lasting time after ablation were significantly lower/shorter in BOXa group than those in CPVa group (14+7% vs 28+10%, p=0.021; 34+22 s vs 70+29 s, p=0.048, respectively). Conclusions In experimental AF model, AF could be prevented by epicardial focused ultrasound ablation. The BOX ablation might be more effective than CPV ablation.