Experimental Findings and Clinical-Pathologic Correlation of Radiofrequency Catheter Ablation at the Left Ventricle Para-Hisian Region.

Zuyi Fu,Weidong Lin,Xi Su,Hai Deng,Shulin Wu,Xianzhang Zhan,Hongyue Wang,Feifan Ouyang,Jinlin Zhang,Xianhong Fang,Fang Zhou Liu,Zili Liao,Yumei Xue,Hongtao Liao

doi:10.3389/fcvm.2021.793903

Abstract

BackgroundCatheter ablation target at the site with large His activation in the left ventricle poses a high risk of atrioventricular (AV) block. We aimed to identify far-field (FF) and near-field (NF) His activation at left upper septum (LUS).MethodsThree-D mapping of the aortic root and left ventricle was performed in 12 dogs. Two sites located at either the base or apex of the triangle interposed between the hinges of the the noncornary coronary cusp (NCC) - right coronary cusp (RCC) were chosen for a single radiofrequency (RF) application. Bipolar and unipolar pacing with different outputs at both sites was attempted to discern NF and FF His activation.ResultsThe sites chosen for NF and FF ablation were located at the base and apex of the triangle, which were 8.03 ± 1.18 mm (group 1) and 3.42 ± 0.61 mm (group 2) away from the RCC-NCC junction. Lower A/V ratios were found in group 1. Pacing could not differentiate NF from FF His activation. In group 1, ablation resulted in III degree AV block in all 6 dogs, whereas neither PR prolongation nor AV block occurred in group 2. Pathologic examination of group 1 showed complete/partial necrosis of the His bundle (HB) and left bundle branch in all 6 dogs. In group 2, no necrosis of the HB was seen in the 6/6 dogs.ConclusionAnatomical localization in the triangle of RCC-NCC junction can help differentiate NF from FF His activation.

Highlights

Understanding the anatomy and identification of near-field (NF) and far-field (FF) His activation of the Para-Hisian (PH) area is critical for catheter ablation of PH arrhythmias (1, 2)
The aim of this study was to investigate the distribution of His activation at the left upper septum (LUS) below the noncornary coronary leaflet (NCL)- right coronary leaflet (RCL) junction, to identify FF and NF His activation within the region using pacing techniques, to deliver a single RF ablation at the apex or base of the triangle interposed between the hinges of the NCL and RCL of the aortic root and to correlate with clinical and pathological characteristics of AV conduction system (AVCS) injury in the canine model
High-density maps in the aortic root and around the LUS below the noncornary coronary cusp (NCC)-right coronary cusp (RCC) junction were successfully achieved with 51 ± 13 points and 56 ± 25 points

Summary

Introduction

Understanding the anatomy and identification of near-field (NF) and far-field (FF) His activation of the Para-Hisian (PH) area is critical for catheter ablation of PH arrhythmias (1, 2). Our strategy is widely used to guide radiofrequency (RF) ablation of right-sided PH arrythmias including PH accessory pathways and ventricular arrhythmias. It was unknown whether this strategy can be extrapolated to left upper septal ablation. The aim of this study was to investigate the distribution of His activation at the left upper septum (LUS) below the noncornary coronary leaflet (NCL)- right coronary leaflet (RCL) junction, to identify FF and NF His activation within the region using pacing techniques, to deliver a single RF ablation at the apex or base of the triangle interposed between the hinges of the NCL and RCL of the aortic root and to correlate with clinical and pathological characteristics of AVCS injury in the canine model. Catheter ablation target at the site with large His activation in the left ventricle poses a high risk of atrioventricular (AV) block. We aimed to identify far-field (FF) and near-field (NF) His activation at left upper septum (LUS)

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Conclusion