Research On The Anatomy And Radiofrequency Catheter Ablation Of Outflow Vract Ventricular Arrhythmias In Children

Outflow tract ventricular arrhythmias(OTVAs)are common in children and adolescents.In experienced medical centers,radiofrequency catheter ablation(RFCA)has been used for ablation of OTVAs in symptomatic children.However,asample and experience are limited on RFCAin children.We collected and analyzed our single center data on 94 consecutive pediatric patients who underwent RFCA for OTVAs from January 2009 to July 2015.We found that their average age of onset was 8.36±4.07(2~16)years.Of these children,68.1%(64/94)was frequency premature ventricular complex.It was the main arrhythmia pattern.And 73.4%(69/94)and 26.6%(25/94)were of right ventricular outflow tract(RVOT)and left ventricular outflow tract(LVOT)origin,respectively.Of these children,RFCA were given up in 2 cases and the total acute success rate was 92.4%(85/92),the follow-up recurrence rate was 8.2%(7/85)and the complications of the procedure were 2.1%(2/94).Only in a single side of RVOT or LVOT,ablation was succeeded in 79 cases and failed in 7 casesandwas given-up in 2 cases.Furthermore,follow-up recurrence rate was 8.9% in these 79 children.However,6 children underwent successful RFCA in both sides of outflow tract and no follow-up recurrence.And their characterists of OTVAs ECG were similar with the adult’s.4 types of ECG algorithm used to locate the origin of OTVAs had a 47.4~71.4% positive predictive value(PPV)for LVOT origin(sensitivity:36.0~68.0%,specificity: 85.5~91.3%).However,the PPV for LCC origin washigher than that for RCC origin with more sensitive and specific in these LVOT origin cases.OTVAs in children originate mostly from RVOT.RFCA can be used for ablation of pediatric OTVAs effectively and safety.In some cases,successful RFCA should be ablated in both sides of outflow tract.Our research provides someexperiences for improving the success rate of ablation for OTVAs in children.ECG-based prediction of OTVA origin as used in adults islimited in children,except for LCC orgin.