Asymmetric Innervation of the Heart

Sudden cardiac death (SCD) is the leading cause of death in the Western world. SCD is thought to result from an interaction between a substrate (a diseased heart) and a trigger. However, the mechanisms of this interaction are poorly understood. Based on the foundational observation that the autonomic innervation of the heart is asymmetric, with sympathetic activation lateralized to the left being more arrhythmogenic than sympathetic activation lateralized to the right, we review evidence for the hypothesis that lateralized brain activation, particularly subcortically, can induce life-threatening ventricular arrhythmias and SCD through lateralized mechanisms. Although not yet conclusive, evidence of lateralized influences on arrhythmogenesis is suggestive and continues to grow. Implications for future research and clinical applications are discussed.