Role of the Autonomic Nervous System in Modulating Cardiac Arrhythmias

Abstract

I n 1628, William Harvey hinted at a link between the brain and the heart when he wrote, "For every affection of the mind that is attended with either pain or pleasure, hope or fear, is the cause of an agitation whose influence extends to the heart."1 For the past half century, numerous anatomic and physiological studies of cardiac autonomic nervous system (ANS) 2-6 have investigated this link and found it to be very complex. Autonomic activation alters not only heart rate, conduction, and hemodynamics, but also cellular and subcellular properties of individual myocytes. The characterization of extrinsic cardiac ANS and intrinsic cardiac ANS ranges from the recognition of anatomic relationships at the gross level to discovery of chemoreceptors, mechanoreceptors, and intracardiac ganglia lining specific regions along the cardiac chambers and great vessels. Moreover, studies beginning >80 years ago [7][8][9] have demonstrated the critical role of cardiac ANS in cardiac arrhythmogenesis. This topic has garnered much recent interest because of mounting evidence showing that neural modulation either by ablation or stimulation can effectively control a wide spectrum of cardiac arrhythmias. [10][11][12][13] In this review, we will briefly discuss the anatomic aspects of cardiac ANS, focusing on how autonomic activities influence cardiac electrophysiology. We will also discuss specific autonomic triggers of various cardiac arrhythmias, including atrial fibrillation (AF), ventricular arrhythmias, and inherited arrhythmia syndromes. Lastly, we will discuss the latest avenues of research and clinical trials regarding the application of neural modulation in the treatment of specific cardiac arrhythmias.

β‐Blocker Therapy Prior to Admission for Acute Coronary Syndrome in Patients Without Heart Failure or Left Ventricular Dysfunction Improves In‐Hospital and 12‐Month Outcome: Results From the GULF‐RACE 2 (Gulf Registry of Acute Coronary Events‐2)

“…In the OPTIMIZE‐HF (Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure) registry, BB did not decrease mortality, rehospitalization, or the combined end point in patients with HF and preserved ejection fraction 19. However, the decreased arrhythmic risk associated with BB therapy has been demonstrated in several studies because BB inhibit the autonomic nervous system,20 hyperactivation of which could trigger arrhythmias 21…”

Neuro-cardiac interaction in malignant ventricular arrhythmia and sudden cardiac death

“…Multiple lines of evidence point to a pivotal role of the autonomic nervous system in the development and maintenance of arrhythmias (Shen & Zipes 2014). ß-blockers have been shown to be of prognostic benefit in certain heart conditions, with data supporting some reduction in SCD mortality (Al-Gobari et al 2013) highlighting an important association between sympathetic tone and ventricular arrhythmias.…”

The epicardium as modulator of the cardiac autonomic response during early development

“…The cardiac autonomic nervous system (cANS) is essential in modulating cardiac function by altering heart rate (chronotropy), conduction velocity (dromotropy) and force of contraction (inotropy) [1]. Dysfunctioning of the cANS plays a role in the pathogenesis of arrhythmias [1] and hypertension [2] and is involved in disease progression in heart failure [3].…”

“…Dysfunctioning of the cANS plays a role in the pathogenesis of arrhythmias [1] and hypertension [2] and is involved in disease progression in heart failure [3]. Furthermore, normal functioning of the cANS is important for the prognosis of adult patients with congenital heart disease [4].…”