Bing Wu1, Shanghua Xu2, Ruozhu Dai1, Meiman Hong1, Haiyun Wu1, Rong Lin1. 1. Department of Cardiology, First Hospital of Quanzhou Affiliated to Fujian Medical University, Quanzhou, Fujian, China. 2. Department of Cardiology, First Hospital of Nanping Affiliated to Fujian Medical University, Nanping, Fujian, China.
Abstract
INTRODUCTION: Previous studies have shown that epicardial ganglionated plexi ablation (EGPA) could increase the risk of ventricular arrhythmias induced by acute myocardial ischemia. However, the long-term effect of EGPA in a canine postmyocardial infarction (MI) model is not well established. MATERIALS AND METHODS: Twenty mongrel dogs were randomly divided into two groups: an MI group (n = 10) and an EGPA group (EGPA plus MI, n = 10). EGPA was achieved by ablation of four major ganglion plexi and the ligament of Marshall. The electrocardiograph (ECG) parameters, ventricular effective refractory period (ERP), inducibility of tachyarrhythmias, and ventricular fibrillation threshold (VFT) were measured at baseline and after 8 weeks. Tyrosine hydroxylase (TH) and nerve growth factor (NGF) expression levels in the peri-infarcted zone were also determined by immunohistochemistry in both groups at the end of the study. RESULTS: No significant differences were found in electrophysiological parameters at the baseline between the two groups. At the end of the 8-week follow-up, however, the EGPA group was associated with a longer QT interval, corrected QT (QTc) interval and ventricular ERP, larger dispersion of QT, QTc, and ERP, and higher inducibility of tachyarrhythmia and VFT when compared to the MI group. In addition, the density of TH and NGF in the peri-infarcted zone was also significantly increased in the EGPA group in comparison to the MI group. CONCLUSIONS: After the 8-week follow-up, EGPA increased the ventricular arrhythmia inducibility in the canine post-MI model, likely by increasing ventricular electrophysiological instability and promoting ventricular sympathetic remodeling.
INTRODUCTION: Previous studies have shown that epicardial ganglionated plexi ablation (EGPA) could increase the risk of ventricular arrhythmias induced by acute myocardial ischemia. However, the long-term effect of EGPA in a caninepostmyocardial infarction (MI) model is not well established. MATERIALS AND METHODS: Twenty mongrel dogs were randomly divided into two groups: an MI group (n = 10) and an EGPA group (EGPA plus MI, n = 10). EGPA was achieved by ablation of four major ganglion plexi and the ligament of Marshall. The electrocardiograph (ECG) parameters, ventricular effective refractory period (ERP), inducibility of tachyarrhythmias, and ventricular fibrillation threshold (VFT) were measured at baseline and after 8 weeks. Tyrosine hydroxylase (TH) and nerve growth factor (NGF) expression levels in the peri-infarcted zone were also determined by immunohistochemistry in both groups at the end of the study. RESULTS: No significant differences were found in electrophysiological parameters at the baseline between the two groups. At the end of the 8-week follow-up, however, the EGPA group was associated with a longer QT interval, corrected QT (QTc) interval and ventricular ERP, larger dispersion of QT, QTc, and ERP, and higher inducibility of tachyarrhythmia and VFT when compared to the MI group. In addition, the density of TH and NGF in the peri-infarcted zone was also significantly increased in the EGPA group in comparison to the MI group. CONCLUSIONS: After the 8-week follow-up, EGPA increased the ventricular arrhythmia inducibility in the canine post-MI model, likely by increasing ventricular electrophysiological instability and promoting ventricular sympathetic remodeling.
Authors: Dan D Nguyen; Nazem Akoum; Jonathan Hourmozdi; Jordan M Prutkin; Melissa Robinson; Deanna M Tregoning; Basil M Saour; Neal A Chatterjee; Arun R Sridhar Journal: Heart Rhythm O2 Date: 2021-09-03