The anatomical basis behind the neuromodulation effects associated with pulmonary vein isolation.

The anatomical basis underlying the neuromodulation effects seen with pulmonary vein (PV) isolation (PVI) is not fully understood. Left atrial (LA) electro-anatomical maps of 38 patients who underwent catheter cardioneuroablation for vagally mediated bradycarrhythmias (VMB) were studied. During the procedure, LA ganglionic plexi (GPs) were systematically identified and ablated. Design PVI lines were created on these maps by a blinded observer, and the degree of overlap between 4 GPs and individual PVs was assessed. 1.7±7 (35.5±17.0%) of the total 31.6±10 GP ablation sites per patient were found to overlap with the design PVI lines. The overlap was higher for the right-sided GPs, P< 0.001. The degree of GP-PV overlap varied: 1 PV in 5 (13.2%) patients, 2 PVs in 15 (39.2%), 3 PVs in 16 (42.1%), and all 4 PVs in 2 (5.3%). No patient had zero GP-PV overlap. A vagal response was most commonly observed during ablation at the left superior GP (89.5%), while a sympathetic response was observed most often during the right superior GP ablation (97.4%). Some degree of GP-PV antral overlap is the norm, and this is more pronounced for the right-sided PVs. There is significant individual variability in the degree of overlap which may explain why neuromodulation effects are not seen universally following PVI. This article is protected by copyright. All rights reserved.