Correlation Of Complete Right Bundle Branch Block With The Atrial Fibrillation And Its Predictive Value For Recurrence After Catheter Ablation Of Paroxysmal Atrial Fibrillation

Background:Atrial fibrillation(AF)is one of the most common rapid cardiac arrhythmias in the general population,characterized by irregular fibrillation waves on the electrocardiogram.The prevalence of AF increases with age.The incidence rate of AF will double every 10 years and the prevalence rate of people over 80 years old is as high as 7.5%.AF can lead to chest tightness,palpitation and other symptoms,affecting daily life and work of AF patients.In severe cases,it also can lead to ischemic stroke,heart failure,cognitive dysfunction and other complications,and is related to the increase of incidence rate and mortality of cardiovascular diseases.Therefore,it is very imperative to diagnose this disease as early as possible,not only to improve the cure rate of AF,but also to reduce the incidence of complications of AF,reducing the mental pressure and economic burden of patients.Catheter ablation of AF has made significant progress in the past decade and has gradually become the main treatment strategy for AF.Numerous studies have shown that catheter ablation therapy for AF is significantly superior to drug therapy in restoring sinus rhythm and improving prognosis.Complete right bundle branch block(CRBBB)is one of the most frequent alterations observed on electrocardiography,and its prevalence increases with age.A prospective study abroad showed that after a 30-year follow-up of 855 men,the prevalence rate was 0.8% at the age of 50 and 11.3% at the age of 80.CRBBB,which was defined as QRS duration of more than 120 milliseconds in right precordial leads,slurred S wave(S-wave duration > R-wave duration)in leads I and V6,as well as RSR’ pattern with R’ taller than R in lead V1 and/or lead V2.CRBBB is generally considered as a benign finding that does not imply an increased risk of cardiovascular diseases when found in asymptomatic healthy individuals.However,these findings are based on a few outdated studies with small sample sizes,and many recent cohort studies have found that CRBBB significantly associated with the increase of major adverse cardiovascular events and allcause mortality,which can increase the long-term cardiovascular risk of the general population.However,the correlation between CRBBB and the onset of AF has not been reported.This study aims to evaluate the correlation between CRBBB and the development of AF,and provide important clinical evidence for the early prevention and treatment of AF.By analyzing the risk factors for recurrence of AF,we evaluated the impact of CRBBB on recurrence after catheter ablation in patients with AF.Part one: Association between Complete Right Bundle Branch Block and Atrial Fibrillation Objective: Complete right bundle branch block(CRBBB)is one of the most frequent alterations observed on electrocardiography.CRBBB is associated with many cardiovascular diseases.However,the association between CRBBB and atrial fibrillation(AF)remains unclear.Methods: We performed a retrospective study of 2,639 patients(male,n = 1,549;female,n = 1,090;mean age,58 ± 13 years).CRBBB was defined as a late R(R’)wave in lead V1 and/or lead V2 with a slurred S wave in leads I and V6 with a prolonged QRS duration(≥120ms).Results: Among the 2,639 patients,CRBBB was detected in 40 patients(1.5%),and the prevalence of AF was 7.4%(196/2,639).The proportion of patients with AF and CRBBB was higher than the proportion of patients with AF without CRBBB(22.5% vs.7.2%;P = 0.001).In the forward multivariate logistic analysis,CRBBB(odds ratio [OR],3.329;95% confidence interval [CI],1.350– 8.211;P = 0.009),complete left bundle branch block(OR,2.209;95% CI,1.238– 3.940;P = 0.007),age(OR,1.020;95% CI,1.005– 1.035;P = 0.009),valvular heart disease(OR,2.332;95% CI,1.531– 3.552;P < 0.001),left atrial diameter(OR,1.133;95% CI,1.104– 1.163;P < 0.001),left ventricular ejection fraction(OR,1.023;95% CI,1.006– 1.041;P = 0.007),and class I or III anti-arrhythmic drug use(OR,10.534;95% CI,7.090– 15.651;P < 0.001)were associated with AF.Conclusion: In conclusion,CRBBB was significantly associated with AF in this study.Part two: Complete Right Bundle Branch Block and a Risk of Recurrence of Paroxysmal Atrial Fibrillation after Catheter Ablation Objective: It has been demonstrated that complete right bundle branch block(CRBBB)is associated with an increased risk of atrial fibrillation(AF).However,the effect of CRBBB on the recurrence of paroxysmal AF after catheter ablation is unclear.Methods: 486 consecutive patients with paroxysmal AF who were hospitalized at our hospital for radiofrequency ablation between January 2018 to December 2020 were retrospectively reviewed.And all of the ECG recordings were analyzed to detect CRBBB.CRBBB was defined as a late R(R’)wave in lead V1 and/or lead V2 with a slurred S wave in leads I and V6 with a prolonged QRS duration(≥120ms).AF recurrence was defined as the occurrence of confirmed atrial tachyarrhythmia lasting more than 30 s beyond 3 months after catheter ablation.Results: Among the 486 patients,CRBBB was detected in 28 patients(5.8%).During a mean follow up of 22.5 ± 9.8 months(range,4–48 months),86(17.7%)patients developed recurrence of AF.The recurrence rate of AF was higher in patients with CRBBB than in those without CRBBB(35.7% vs.16.6%,P=0.02).Multivariable Cox proportional hazards regression analysis showed that CRBBB[(hazard ratio,HR),2.296,95% confidence interval(CI),1.172-4.499;P=0.015 ],heart failure(HR,3.589,95%CI,1.537-8.377;P=0.003)were associated with the risk of recurrence.Conclusion: Patients with CRBBB have an increased risk of AF recurrence after catheter ablation.