The Relationship Between Total Atrial Conduction Time And Recurrence Of Paroxysmal Atrial Fibrillation After Radiofrequency Catheter Ablation

Background:For most types of atrial fibrillation(AF), catheter ablation(CA) has become a standard therapy strategy and with well-documented efficacy, mainly with pulmonary vein isolation(PVI). CA reduces AF burden and increases quality of life in symptomatic patients with AF. Nevertheless, reported rates of AF recurrence after CA vary widely in the published literature(between 10% and 60%). Meta-analyses reveal that no single preablation patient characteristic efficiently predicts AF recurrence. Studies have shown that atrial conduction time(TACT) is a risk factor for atrial fibrillation and can predict AF recurrence after CA. The purpose of this study was to explore the relationship between TACT and AF recurrence after radiofrequency catheter ablation(RFCA) in patients with paroxysmal atrial fibrillation.Objectives:Our aim ws to evaluate the efficacy of radiofrequency catheter ablation in patients with paroxysmal atrial fibrillation in our center,and to investigate the relationship between total atrial conduction time(TATC)and AF recurrence after radiofrequency catheter ablation(RFCA) in patients with paroxysmal atrial fibrillation.Methods: 123 patients(72males,51females) with paroxysmal atrial fibrillation who underwent RFCA in the Department of cardiology from 2012 to 2014 were consecutively enrolled in this study, and collect the general clinical data of the patients.When patients were in sinus rhythm before RFCA,TACT was estimated by measuring the time delay between the onset of the P-wave in lead II of the surface electrocardiogram and the peak A’-wave on the tissue Doppler tracing of the left atrial lateral wall(PA-TDI duration), 3 cardiac cycles were measured and their mean values were determined.Clinical success was assessed after 3-month blanking period and all patients were follow-up for 12 months. According to the results of the follow-up, the patients were divided into recurrent group and unrecurrent group, and analyze the influence of TACT on AF recurrence after RFCA.Results: After a follow-up of 12 months, 5 patients(4%) lost to follow-up, 36 patients(30.5%) had recurrent AF whereas 82 patients(69.5%) maintained sinus rhythm.Univariate analysis showed that the proportion of men with unrecurrent group was higher than the recurrent group(P=0.04), and the longer duration of patients with paroxysmal atrial fibrillation, the greater risk of AF recurrence after RFCA(P=0.04).In addition, the mean left atrial volume index(LAVI) of the recurrent group of patients was larger than that of the unrecurrent group of patients(43±12 vs. 38±10ml/m2,P=0.016),and the mean TACT of the recurrent group of patients was longer than that of the unrecurrent group of patients(144±21 vs.122±23ms,P<0.001). Multivariate Cox proportional hazard analyses showed that LAVI(HR: 1.030, P=0.03) and TACT(HR: 1.032, P<0.001) were identified as independent predictors of AF recurrence.However, receiver operator characteristics(ROC) curve analyses demonstrated that TACT had a superior accuracy to predict AF recurrence compared with LAVI(area under the curve 0.781 vs. 0.633,P=0.048).Conclusion: In this study, the recurrence rate of patients with paroxysmal atrial fibrillation after RFCA was 30.5% after 12 months follow-up. The difference between recurrent group and unrecurrent group in gender, duration of AF, LAVI and TACT had a statistical significance. TACT and LAVI are independent risk factors for AF recurrence after RFCA. The predictive value of TACT for AF recurrence after RFCA is better than LAVI.