Ganglionated plexi explained

Ganglionated plexi (GP) comprise the intrinsic cardiac autonomic nervous system composed of autonomic ganglia of the heart atrium and ventricles.^[1] The GP are embedded in the epicardial fat pads, consisting of only a few neurons or as many as 400 neurons. GP are spatially close to the pulmonary veins, such that pulmonary vein isolation necessarily affects the GP.^{[2] [3]} GP has been shown to be a contributor to atrial fibrillation (AFib), such that ablation of the GP has been a strategy for treatment of AFib. Pulsed field ablation has shown to be an AFib ablation strategy which effectively destroys the GP.^[4] GP ablation alone has been shown to eliminate AFib in approximately three-quarter of AFib patients.

Ligation of the left atrial appendage may reduce AFib by alteration of the GP.^[5]

There are intrinsic plexuses that form part of the autonomic nervous system (ANS),^[6] the best known intrinsic plexus being the enteric nervous system. The GP are part of the cardiac intrinsic ANS.^[7]

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.^[8]

In humans, the ganglia are mostly associated with the posterior or superior aspect of the atria.^[9] 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.^[10]

Notes and References

1. Stavrakis S, Po S . Ganglionated Plexi Ablation: Physiology and Clinical Applications . Arrhythmia & Electrophysiology Review . 6 . 4 . 186–190 . 2017. 10.15420/aer2017.26.1 . 5739885 . 29326833 .
2. SHu F, Zheng L, Yao Y . Avoidance of Vagal Response During Circumferential Pulmonary Vein Isolation: Effect of Initiating Isolation From Right Anterior Ganglionated Plexi . Circulation: Arrhythmia and Electrophysiology . 12 . 12 . e007811 . 2019. 10.1161/CIRCEP.119.007811 . 31760820 .
3. Zheng S, Zeng Y, Meng X . Active ganglionated plexi is a predictor of atrial fibrillation recurrence after minimally invasive surgical ablation . . 29 . 2 . 279-285 . 2014 . 10.1111/jocs.12299 . 24517359 . free .
4. Bradley CJ, Haines DE . Pulsed field ablation for pulmonary vein isolation in the treatment of atrial fibrillation . . 31 . 8 . 2136-2147 . 2020 . 10.1111/jce.14414 . 32107812 .
5. AlTurki A, Huynh T, Essebag V . Left atrial appendage isolation in atrial fibrillation catheter ablation: A meta-analysis . Journal of Arrhythmia . 34 . 5 . 478-484 . 2018. 10.1002/joa3.12095 . 6174377 . 30327692 .
6. Wake . Emily . Brack . Kieran . Characterization of the intrinsic cardiac nervous system . Autonomic Neuroscience . August 2016 . 199 . 3–16 . 10.1016/j.autneu.2016.08.006.
7. Calkins H, Hindricks G, Yamane T . 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation . . 20 . 1 . e1-e160 . 2018 . 10.1093/europace/eux274 . 5834122 . 29016840 .
8. Hardwick . Jean C. . Baran . Caitlin N. . Southerland . E. Marie . Ardell . Jeffrey L. . Remodeling of the guinea pig intrinsic cardiac plexus with chronic pressure overload . American Journal of Physiology-Regulatory, Integrative and Comparative Physiology . September 2009 . 297 . 3 . R859–R866 . 10.1152/ajpregu.00245.2009. 2739792 .
9. Smith . R. B. . The occurrence and location of intrinsic cardiac ganglia and nerve plexuses in the human neonate . The Anatomical Record . January 1971 . 169 . 1 . 33–40 . 10.1002/ar.1091690104.
10. Aksu . Tolga . Gopinathannair . Rakesh . Gupta . Dhiraj . Pauza . Dainius H. . Intrinsic cardiac autonomic nervous system: What do clinical electrophysiologists need to know about the “heart brain”? . Journal of Cardiovascular Electrophysiology . June 2021 . 32 . 6 . 1737–1747 . 10.1111/jce.15058.