Effects Of Substrate Modified Ablation Strategy Under The Guidance Of Voltage Scaling In Sinus Rhythm On The Success Rate Of Paroxysmal Atrial Fibrillation Ablation

Objective: The purpose of this study is to investigate the effect of left atrial with low voltage zone on radiofrequency ablation in patients with paroxysmal atrial fibrillation,and to evaluate the effect of voltage-based substrate modified surgery in sinus rhythm on success rate of radiofrequency ablation in patients with paroxysmal atrial fibrillation.Methods:Patients with paroxysmal atrial fibrillation who underwent catheter ablation for the first time in the 4th department of cardiology,the second hospital of hebei medical university from October 2017 to October 2018 were selected.First,all patients were subjected to CPVI surgery under the guidance of Carto 3 mapping system.After isolated pulmonary vein potential,Lasso ring electrode was used for voltage mapping in the left atrium under sinus rhythm to mark the low voltage zone(0.1-0.5mV)and the transition zone(0.4-1.3mV).Patients with negative left atrial voltage(no LVZ or TZ)were referred to as the normal substrate group,and the operation was directly completed;And who marked LVZ and TZ of the left atrium are referred to as the low-voltage group,then the low-voltage group were randomly divided into two subgroups that called the simple CPVI and substrate modified groups.the former ended the operation.In contrast,the left atrial low-voltage zone(LVZ)and the transition zone(TZ)were treated by individualized substrate ablation in the substrate modified group.Routine follow-up was conducted every month after the postoperative blank period(Three months).and the electrocardiogram(ECG)was reviewed at any time if the patient has palpitations.The follow-up included telephone counseling,ECG and 24-hour Holter.Recurrent atrial fibrillation was defined as atrial fibrillation detected by ECG or 24-hour Holter with a duration of more than 1 minute after the postoperative blank period(Three months).The recurrence of AF in each group and each subgroup was compared.Results:1.the average postoperative follow-up 9±3.24 months(4-15 months)found that clinical data between the groups with and without recurrence of recurrence of the single factor analysis showed that variable,in the two groups of age,left atrial diameter and ejection fraction,gender and index of low voltage zone,only left atrial low voltage(P = 0.019)and left atrial diameter(P = 0.034)is a predictor of recurrence of paroxysmal atrial fibrillation.Further Logistic multivariate analysis of left atrial diameter and left atrial low voltage suggested that left atrial low voltage was an independent risk factor for atrial fibrillation recurrence after radiofrequency ablation(P=0.010,RR: 2.383,95%ci: 1.231-4.615).2.comparing the clinical characteristics of the low-voltage group and the normal substrate group,it was found that the age of the former group was higher(P=0.038),the left atrial diameter was larger(P= 0.040),and the ablation time was longer(P= 0.009).At the same time,the study showed that the success rate of the normal substrate group was significantly higher than that of the patients with low-voltage group(P=0.035)in the average follow-up of 9±3.24 months.Kaplan-meier analysis showed that the sinus rhythm maintenance rate at the 12 month follow-up was 55.76% in the low-voltage group and 76.17% in the normal substrate group(Log Rank test P=0.018).3.subgroup analysis showed that during a 9±3.24 months follow-up period,For the paroxysmal atrial fibrillation patients who with LVZ or TZ in left atrial,the success rate of substrate modified under the guidance of voltage mapping was significantly higher than that of the simple CPVI group(P=0.026).Kaplan-meier analysis showed that sinus rhythm maintenance rates were estimated to be 68.65% in the substrate modified group and 42.15% in the simple CPVI group at the 12 months follow-up respectively(Log Rank test P=0.012).Conclusions:1.The presence of LVZ or TZ in left atrial is an independent predictor of postoperative recurrence with paroxysmal atrial fibrillation.2.The postoperative success rate of paroxysmal atrial fibrillation with normal substrate in left atrial is significantly higher than that with LVZ or TZ.3.For the paroxysmal atrial fibrillation with LVZ or TZ in left atrial,the postoperative success rate of catheter ablation can be significantly improved by adopting the substrate ablation strategy in the left atrium during sinus rhythm under the guidance of voltage mapping while CPVI.