The cardiac autonomic nervous system (ANS) can be divided into the extrinsic and intrinsic ANS.100 The extrinsic cardiac ANS consists of sympathetic and parasympathetic components,101,102 and includes neurons in the brain and spinal cord and nerves directed to the heart. The intrinsic ANS primarily includes thousands of autonomic neurons and nerves located in ganglionated plexi (GP), which are transitioned to the epicardial fat pads outside the heart and along the great vessels in the thorax.100,103,104 There are 7 major GP, including 4 located in the LA around the PVs.103,105 The ligament of Marshall, which also contains GP, plays a coordination role between the extrinsic and intrinsic ANS.106 The GP predominantly contain parasympathetic neurons, but also sympathetic neurons. In humans, numerous autonomic nerves are located at the PV–LA junction. The nerve densities are much more pronounced within 5 mm of the PV–LA junction and are higher in the epicardial surface than in the endocardium.107,108 These data reveal that the areas of LA endocardial surface most suitable for ANS modification are located in the immediate vicinity of the PV–LA junction. Due to close relationship of the sympathetic and parasympathetic ANS components, it is difficult to perform selective radiofrequency (RF) ablation of a particular part of the ANS,109 and ablation of these sites can destroy both adrenergic and cholinergic nerves.