Sex Differences in Electrophysiology and Calcium Handling in Atrial Health and Fibrillation.

The importance of biological sex on disease etiology and outcomes has long been underinvestigated. While recent focus on characterizing sex differences in cardiac pathophysiology has led to improved inclusion of both sexes in scientific studies and clinical trials, much is still unknown about underlying differences in normal cardiac physiology. This is particularly true for the atria, where the most common arrhythmia, atrial fibrillation (AF), occurs. AF is associated with adverse structural, electrophysiological, and calcium handling remodeling that leads to patient morbidity and mortality. Differences in the onset, prevalence, presentation, and prognosis of AF are known to differ between males and females, yet the sex-specific baseline phenotypes from which AF arises are not well characterized. This review examines what is currently known about sex differences in atrial physiology, the alterations that occur in AF, potential mechanisms underlying sex divergence, and the need for sex-targeted therapeutic strategies.