The Comparison Study Between The Epicardial Catheter Ablation And Endocardial Catheter Ablation In Treatment Of Atrial Fibrillation

Background atrial fibrillation (AF) is a supraventricular tachyarrhythmia characterized by uncoordinated atrial activation with associated deterioration of atrial mechanical function. It is the most common cardiac arrhythmia, becomes more prevalent with age, and is associated with an increased long-term risk of stroke, heart failure, and all-caused mortality. AF can occur in the absence of underlying heart disease but is more frequent in connection with mitral valve disease, heart failure, ischemic heart disease, and hypertension. It is well accepted that the development AF requires both a trigger and a susceptible substrate. The goals of AF ablation procedures are to prevent AF by either eliminating the trigger that initiates AF or by altering the arrhythmogenic substrate. The most commonly employed ablation strategy today, which involves the electrical isolation of the PVs by segmental ablation incision (SPVI) or by creation of circumferential lesions around the right and the left PV ostia (CPVA), probably impacts both the trigger and substrate of AF. The classic Maze procedure can eliminate AF in more than 90% of patients. A complex but safe operation, the maze procedure has been applied by relatively few surgeons. However, recent advances in the understanding of the pathogenesis of AF and development of new ablation technologies enable surgeons to perform pulmonary vein ablation, create linear left atrial lesions, and remove the left atrial appendage rapidly and safely. Recently developed surgical instrumentation now enable thoracoscopic and keyhole approaches, facilitating extension of epicardial AF ablation and excision of the left atrial appendage to patients with isolated AF and no other indication for cardiac surgery.Objective To compare the effect of ablation on atrium between epicardial circumferential pulmonary vein ablation (CPVA) and endocardial CPVA to cure atrial fibrillation (AF).Methods Twenty canines were divided into two groups randomly. All of them underwent 64-slice multislice computed tomography (64-CT) before catheter ablation. Guided by image fusing of 64-CT with electroanatomic mapping, group A underwent epicardial CPVA and group B underwent endocardial CPVA. We observed inducibility of AF, vagal denervation, isolation of pulmonary vein, atrial effective refractory period (AERP), AERP dispersion before and after ablation.Results Inducibility of AF before and after ablation (group A 66/100 vs 18/100, P<0.05; group B 60/100 vs 20/100, P<0.05), vagal denervation (group A 8/10 vs group B 5/10, P=0.1749), isolation of left super pulmonary vein (LSPV) (group A 1/10 vs group B 4/10, P=0.1517), isolation of RSPV(group A 2/10 vs group B 5/10, P=0.1749), AERP (group A 95.5±10.9ms vs 101±3.2ms , P=0. 185; group B 90.5±10.7ms vs 105±4.1ms, P<0.05), AERP dispersion (group A 28.5±8.12ms vs 8.5±4.74 ms, P<0.05; group B 27±6.32ms vs 9.5±4.38ms, P<0.05). No acute injure happened to coronary artery in two groups.Conclusion Both epicardial CPVA and endicardial CPVA can suppress the inducibility of AF. Epicardial CPVA can be performed guided by Carto Merge image safely.