Neurocardiac Crosstalk: Sympathetic Remodeling and Arrhythmogenesis After Myocardial Infarction.

Sympathetic remodeling following myocardial infarction (MI) is a critical mechanism underlying the development of malignant arrhythmias and sudden cardiac death (SCD). The cardiac sympathetic nervous system functions as a multi-level regulatory network, integrating centers from the cerebral cortex (e.g., the insular lobe and anterior cingulate gyrus), subcortical structures (e.g., the paraventricular nucleus of the hypothalamus), and brainstem nuclei (e.g., the rostral ventrolateral medulla and nucleus of the solitary tract), down to the peripheral ganglia. Post-MI, this entire neural axis undergoes significant remodeling, which manifests as neuroinflammation in the central nervous system, alongside peripheral sympathetic nerve sprouting and heterogeneous hyperinnervation. This article provides a systematic review of the anatomical architecture of the cardiac sympathetic nerve and the regulatory mechanisms of sympathetic remodeling at various levels of the central nervous system after MI. It particularly focuses on key signaling pathways-including the TLR4/MyD88/NF-κB and P2X7R/NLRP3 inflammasome pathways, as well as GABAergic inhibition within the paraventricular nucleus-in addition to the peripheral remodeling mechanisms within the stellate ganglia. By synthesizing insights from these studies, this review offers a novel perspective for understanding the neuroimmune mechanisms of post-MI malignant arrhythmias and provides a theoretical foundation for elucidating the mechanisms of SCD in clinical practice.