Catheter based cardioneuroablation is increasingly being utilized to improve outcomes in patients with vasovagal syncope and functional atrioventricular block. There is now increasing convergence amongst enthusiasts on its various aspects, including patient selection, technical steps, and procedural end-points. This pragmatic review aims to take the reader through a step-by-step approach to cardioneuroablation: we begin with a brief overview of the anatomy of intrinsic cardiac autonomic nervous system, before focusing on the indications, pre- and post-procedure management, necessary equipment, and its potential limitations.

It is increasingly recognized that the autonomic nervous system (ANS) is a major contributor in many cardiac arrhythmias. Cardiac ANS can be divided into extrinsic and intrinsic parts according to the course of nerve fibers and localization of ganglia and neuron bodies. Although the role of extrinsic part has historically gained more attention, the intrinsic cardiac ANS may affect cardiac function independently as well as influence the effects of the extrinsic nerves. Catheter based modulation of the intrinsic cardiac ANS is emerging as a novel therapy for management of patients with brady and tachy arrhythmias resulting from hyperactive vagal activation. However, distribution of intrinsic cardiac nerve plexus in the human heart and the functional properties of intrinsic cardiac neural elements remain insufficiently understood. The present review aims to bring the clinical and anatomical elements of the ICANS together, by reviewing neuroanatomical terminologies and physiological functions, in order to guide the clinical electrophysiologist in the catheter lab, and to serve as a reference for further research.

Demonstration that the myocardial sleeves of the pulmonary veins (PVs) are the main triggering and maintaining foci for paroxysmal atrial fibrillation (AF) have stimulated studies investigating electrophysiological properties of PVs and the adjacent left atrial (LA) myocardium. It has been shown that PV myocytes have a shorter action potential duration and are more prone to effects of local autonomic nerve stimulation in terms of shortening of action potential duration, early after depolarization formation and triggered firing compared to left atrial myocytes (1). The intrinsic cardiac autonomic nervous system (ICANS) forms clusters of neurons called ganglionic plexi (GPs), and studies using histologic examination of heart sections have shown that these GPs are localized preferentially at certain epicardial sites adjacent to the left and right atria (2). The precise role of ICANS in AF continues to be an area of intense research (3), and matters are not helped by the uncertainty regarding the best way to identify and target ICANS peri-procedurally. As there can be significant variability of GP sites in individual patients, endocardial high-frequency stimulation (HFS) has been used to aid their localization in the electrophysiology laboratory (4).