R/S Ratio in Lead III Predicts Successful Ablation of Ventricular Arrhythmias Originating in Para-Hisian Region

• Published in: JACC. Clinical electrophysiology Vol. 7; no. 6; pp. 719 - 730
• Main Authors: Yue-Chun, Li, Yuan-Nan, Lin, Jing, Xu, Yang-Qi, Pan, Cheng, Zheng, Yang-Jing, Xue, Jia-Xuan, Lin, Jin, Li, Jia, Li, Jia-Feng, Lin
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2021
• Subjects: catheter ablation; His bundle; left ventricle; para-Hisian region; right ventricle; ventricular arrhythmias; EVAS; RV; left ventricle; ASOV; RV-HB; LV; LV-HB; NPV; para-Hisian region; PPV; FA group; SA group; ROC; ECG; catheter ablation; VA; AVB; 3D; right ventricle; RFCA; ventricular arrhythmias; AV; His bundle; HB; S1
• ISSN: 2405-500X; 2405-5018
• DOI: 10.1016/j.jacep.2020.10.012

The aim of this study was to investigate the electrocardiographic characteristics of ventricular arrhythmias (VAs) originating near the His bundle (HB) and use the R/S ratio in lead III (RIII/SIII ratio) to predict successful ablation of para-Hisian VAs. Catheter ablation for idiopathic VAs near the HB is often challenging, and data are limited. The present study included 134 consecutive patients undergoing catheter ablation of para-Hisian VAs. The electrocardiographic characteristics in these patients were retrospectively evaluated with successful ablation and failed ablation. Successful ablation was achieved in 115 (85.8%) of the 134 patients. There was no significant difference in QRS duration between the successful and the failed ablation groups. The ablation success rate was significantly lower for para-Hisian VAs with a predominantly positive R wave in lead III than those with a predominantly negative S wave in lead III. The significant factor associated with successful ablation was the RIII/SIII ratio. The RIII/SIII ratio ≤1.1 predicted the successful ablation of para-Hisian VAs with high sensitivity (80.9%) and specificity (94.7%). The RIII/SIII ratio of >1.2 had high sensitivity (100.0%) and specificity (82.8%) to predict the distance <5 mm from the site of origin of para-Hisian VAs to the site recording the largest HB potential. The RIII/SIII ratio was a helpful predictor of the successful ablation of VAs originating in the vicinity of the HB. This may be useful for planning ablation of para-Hisian VAs and minimizing the risk of inadvertent atrioventricular block. [Display omitted]