Circumferential Pulmonary Vein Isolation Plus Electrophysiological Substrate Ablation In The Left Atrium During Sinus Rhythm For The Treatment Of Non-paroxysmal Atrial Fibrillation

Objective The high prevalence of postprocedural atrial tachycardia(AT)attenuates the total success rate of extensive ablation approaches to treat non-paraxysmal atrial fibrillation(NPAF).We hypothesized that after circumferential pulmonary vein isolation(CPVI)and cavotricuspid isthmus(CTI)block were achieved in NPAF patients,the low voltage zones(LVZ)and sites with abnormal electrogram during sinus rhythm(SR-AE)in the left atrium(LA)may be appropriate targets for substrate-based AF ablation.Methods A total of 86 consecutive patients(mean age 52.6±10.0 years;left atrial diameter 41.2±6.0 mm)with NPAF were included in our study group.After CPVI,CTI ablation and cardioversion to SR,high-density mapping of LA was performed.Areas with low-voltage and SR-AEs were targeted for further homogenization and elimination,respectively;78 consecutive sex-and age-matched NPAF patients who were treated with the stepwise approach served as the historical control group.Patient baseline characteristics were comparable between groups.Electrocardiogram was recorded according to symptoms and 24 hour or 7 day Holter monitoring was performed at 3,6,and 12 months.The primary endpoint of this study was any atrial tachyarrhythmia recurrence lasting?30 seconds.Results In the study group,successful CPVI and bidirectional block were achieved in all patients.92%(79/86)patients were successfully cardioverted after CPVI and CTI blocked.Among the patients converted to SR,70%(55/79)patients had LVZ and SR-AEs and received additional ablation,whereas in 30%(24/79)without SR-AEs or LVZ,no further ablation was processed.Compared with the study group,the historical control group had higher procedure duration(211 ? 34.3 minutes vs.182.3? 35.7 minutes;P<0.001)and fluoroscopy time(30.8±8.8 minutes vs.22.6± 9.8 minutes;P = 0.002).During a mean follow-up period of>30 months,the Kaplan-Meier estimated probability to maintain SR at 24 months was 69.8%versus 51.3%.And after a single procedure,3.5%(3/86)developed postprocedural AT in study group,compared with 30%(24/78)in control group(P = 0.0003).Conclusions In conclusion,this pilot study demonstrated that compared with stepwise approach,in patients with NPAF,additional electrophysiological substrate-based ablation during sinus rhythm after CPVI and CTI ablation was more effective with higher sinus rhythm maintenance,lower procedure duration,less fluoroscopy time and a lower incidence of postprocedural AT.