The Intrinsic Cardiac Nervous System and Its Role in Cardiac Pacemaking and Conduction

Area of Science:

• Cardiology
• Neuroscience
• Physiology

Background:

• The cardiac autonomic nervous system (CANS) regulates cardiac activity, and its dysfunction is linked to heart diseases, notably arrhythmias.
• The CANS includes extrinsic and intrinsic components; the intrinsic cardiac nervous system (ICNS) is a network of intracardiac ganglia and neurons.
• Cardiac ganglia modulate cardiac electrophysiology, integrating extrinsic and ICNS inputs.

Purpose of the Study:

• To elucidate the role of the ICNS in modulating the cardiac conduction system for targeted arrhythmia therapies.
• To describe the embryonic development, anatomy, and physiology of the ICNS.
• To correlate intracardiac neuron topography with biophysical/neurochemical properties to define their physiological role.

Main Methods:

• Review of existing literature on ICNS development, anatomy, and physiology.
• Correlation of intracardiac neuron topography with known biophysical and neurochemical properties.
• Analysis of the physiological role of ICNS in controlling sinoatrial and atrioventricular node pacemaker activity.

Main Results:

• The ICNS, comprising intracardiac ganglia and neurons, plays a critical role in cardiac electrophysiology.
• The topography and properties of intracardiac neurons suggest a significant role in regulating pacemaker activity.
• Dysregulation of the ICNS is implicated in various cardiac disorders, including arrhythmias.

Conclusions:

• A comprehensive understanding of ICNS physiology and pathophysiology is essential for developing targeted therapies for cardiac arrhythmias.
• Further research is needed to address open questions regarding the ICNS's role in cardiac health and disease.