Ganglionated plexi

Ganglionated plexi (GP) comprise the intrinsic cardiac autonomic nervous system composed of autonomic ganglia of the heart atrium and ventricles. The GP are embedded in the epicardial fat pads, consisting of only a few neurons or as many as 400 neurons. GP has been shown to be a contributor to atrial fibrillation, such that ablation of the GP has been a strategy for treatment of atrial fibrillation. Addition of GP ablation to pulmonary vein isolation has not improved outcomes, but possibly other methods of GP ablation would be more successful.

There are intrinsic plexuses that form part of the autonomic nervous system (ANS), the best known intrinsic plexus being the enteric nervous system. The GP are part of the cardiac intrinsic ANS.

In animal models, cardiac overload leads to change in the electrophysiological properties of these neurons, leading to the suggestion that such changes might be relevant to the pathophysiology of heart failure.

In humans, the ganglia are mostly associated with the posterior or superior aspect of the atria. The ganglia mediate at least some of the effects of vagal nerve stimulation on the sinoatrial node, although don't seem to mediate atrioventricular node conduction.