Long-term Outcomes Of Catheter Ablation For Idiopathic Premature Ventricular Contractions Originating From The Right Ventricular Inflow Tract

Backgroud and ObjectivePremature ventricular contractions(PVCs)are more common arrhythmias,and their occurrence is quite extensive,including a variety of heart disease patients and normal and healthy people.The clinical manifestations of PVCs are very different,from asymptomatic,mild palpitation discomfort,to premature beat triggering malignant ventricular arrhythmia caused syncope or blackness,and its clinical symptoms have no parallel relationship with prognosis.The clinical prognosis of PVCs with different causes is different.In addition to drug therapy,radiofrequency ablation(RFCA)is another important treatment strategy for arrhythmias,the right ventricular outflow tract is the most common place of origin for idiopathic ventricular premature/ventricular tachycardia and can be treated with RFCA with a high success rate.However,PVCs originating from the right ventricular inflow tract(RVIT),including the tricuspid annulusand the right ventricle basal,is a challenge for successful ablation.This study retrospectively analyzed the short-to-medium-term and long-term effects of radiofrequency ablation on PVCs originating from the RVIT.MethodsWe retrospectively screened 1037 RFCA procedures for idiopathic ventricular arrhythmia,between January 1,2008 and June 31,2012,at Changhai Hospital,Shanghai,to identify patients with PVCs originating from the RVIT.Demographic,clinical characteristics and the data of transcatheter cardiac mapping and ablation were analyzed.Patients were followed up for ECG and 24-hour Holtermonitoring.Delayed efficacy and transient recurrence were evaluated in all patients.Final clinical outcomes and predictors were analyzed.ResultIn total,106 patients(mean age 50.3 ± 17.8 years;52 male)with PVCs originating from the RVIT were enrolled.Ninety-three patients(87.7%)reached acute procedural success by the end of the procedure.Twenty-six of them(28.0%)had early recurrence of PVCs after RFCA,among whom 22 patients showed transient recurrence and the remaining 4 patients still had a significant number of PVCs after seven-day observation.Delayed efficacy was observed in 8/13(61.5%)patients after ablation,one(12.5%)of whom was free of PVCs and the rest 7 patients showed PVCs reduction at the 3-month follow-up(20112±7312 VS 6745±3187,P=0.01),nonetheless,the amount of PVCs returned to that before ablation by the end of follow-up.During a mean follow-up of 49.8±29.5 months,the final success rate of all 106 patients was 68.9%.The outcomes of ablation for different distinct anatomic segments also varied.Delayed efficacy,early recurrence and ablation without the reversed U-curve technique were predictors of final procedural failure.In procedures with the reversed U-curve ablation technique used,the final ablation outcomes were significantly improved(P = 0.001).ConclusionPVCs originating from the RVIT are not uncommon.The majority of patients can be cured by catheter ablation.Delayed efficacy and transient recurrence were both common and predicted final procedure failure after long-term follow-up.The reversed U-curve ablation technique may help reduce early recurrence and improve final ablation outcome.