The Brain–Heart Axis as a Unified Physiological System: Implications for Disease and Therapy

Abstract

The brain-heart axis constitutes a sophisticated, bidirectional communication network fundamental to cardiovascular homeostasis and a critical determinant of disease pathogenesis. This review synthesizes the integrated multi-level architecture of this axis, from its anatomical foundations to its pathophysiological dysregulation. The dialogue is mediated through neural, hormonal, and immune pathways, orchestrated by a hierarchical innervation system comprising extrinsic central command and an intrinsic cardiac nervous system. Under physiological conditions, a dynamic balance between sympathetic and parasympathetic tones, refined by immune feedback, ensures adaptive responsiveness. However, following injury such as a myocardial infarction, this axis undergoes catastrophic maladaptive remodeling. This is characterized by a triad of peripheral sympathetic hyperinnervation and arrhythmogenic nerve sprouting, central neuroinflammation in autonomic centers, and a loss of protective parasympathetic tone. These processes form a selfperpetuating vicious cycle that drives disease progression toward heart failure and sudden cardiac death. This paradigm shift—from a cardiocentric to a neurocardiac perspective—reveals the brain-heart axis not merely as a communication channel but as an integrated physiological unit whose dysfunction is central to cardiovascular pathology. It consequently illuminates novel therapeutic frontiers, including bioelectronic neuromodulation and targeted anti-inflammatory strategies, aimed at restoring axis harmony.