Ischemia-induced ventricular proarrhythmia and cardiovascular autonomic dysreflexia after cardioneuroablation

BACKGROUND Cardioneuroablation (CNA) is an attractive treat-ment of vasovagal syncope. Its long-term efficacy and safety remain unknown. OBJECTIVE The purpose of this study was to develop a chronic porcine model of CNA to examine the susceptibility to ventricular tachyarrhythmia (ventricular tachycardia/ventricular fibrillation [VT/VF]) and cardiac autonomic function after CNA. METHODS A percutaneous CNA model was developed by ablation of left-and right-sided ganglionated plexi (n = 5), confirmed by his-tology. Reproducible bilateral vagal denervation was confirmed af-ter CNA by extracardiac vagal nerve stimulation (VNS) and histology. Chronic studies included 16 pigs randomized to CNA (n = 8) and sham ablation (n = 8, Control). After 6 weeks, animals underwent hemodynamic studies, assessment of cardiac sympa-thetic and parasympathetic function using sympathetic chain stim-ulation and direct VNS, respectively, and proarrhythmic potential after left anterior descending (LAD) coronary artery ligation. RESULTS After CNA, extracardiac VNS responses remained abol-ished for 6 weeks despite ganglia remaining in ablated ganglionated plexi. In the CNA group, direct VNS resulted in paradoxical increases in blood pressure, but not in sham-ablated animals (CNA group vs sham group: 8.36% +/- 7.0% vs -4.83% +/- 8.7%, respectively; P = .009). Left sympathetic chain stimulation (8 Hz) induced signif-icant corrected QT interval prolongation in the CNA group vs the sham group (11.23% +/- 4.0% vs 1.49% +/- 4.0%, respectively; P < .001). VT/VF after LAD ligation was more prevalent and occurred earlier in the CNA group than in the control group (61.44 +/- 73.7 seconds vs 245.11 +/- 104.0 seconds, respectively; P = .002). CONCLUSION 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 susceptibility to VT/VF in ischemia. These potential long-term negative effects of CNA suggest the need for rigorous clinical studies on CNA.