UCLA

Background

Cardioneuroablation (CNA) is an attractive treatment for vasovagal syncope. Its long-term efficacy and safety remain unknown. ObjectiveTo develop a chronic porcine model of CNA to examine ventricular tachyarrhythmia (VT/VF) susceptibility and cardiac autonomic function after CNA.

Methods

A percutaneous CNA model was developed by ablation of left- and right-sided ganglionated plexi (GP)(n=5), confirmed by histology. Reproducible bilateral vagal denervation was confirmed following CNA by extracardiac vagal nerve stimulation (ECVNS) and histology. Chronic studies included 16 pigs randomized to CNA (n=8) and sham ablation (n=8). After 6 weeks, animals underwent hemodynamic studies, assessment of cardiac sympathetic and parasympathetic function using sympathetic chain stimulation (SCS) and direct VNS respectively, and proarrhythmic potential following left anterior descending coronary artery (LAD) ligation.

Results

After CNA, ECVNS responses remained abolished for 6 weeks despite ganglia remaining in ablated GPs. In the CNA group, direct VNS resulted in paradoxical increases in blood pressure, but not in sham animals (CNA group vs. sham: 8.36±7.0% vs. -4.83±8.7%, respectively, p=0.009). Left SCS (8Hz) induced significant QTc prolongation in the CNA group vs. sham (11.23±4.0% vs. 1.49±4.0%, respectively, p<0.001). VT/VF after LAD ligation was more prevalent and occurred earlier in the CNA group vs. control (61.44±73.7sec vs. 245.11±104.0 sec, respectively, p=0.002).

Conclusions

Cardiac vagal denervation is maintained long-term after CNA in a porcine model. However, chronic CNA was associated with cardiovascular dysreflexia, diminished cardioprotective effects of cardiac vagal tone, and increased VT/VF susceptibility in ischemia. These potential long-term negative impacts of CNA suggest the need for rigorous clinical studies on CNA.