Time's imprint on the left atrium: aging and atrial myopathy.

Aging is a primary driver of atrial remodeling and dysfunction, and contributes to the increasing prevalence of atrial myopathy in the aging population. Atrial myopathy, characterized by structural, functional, and electrophysiological abnormalities of the atria, is a key pathological process underlying adverse cardiovascular outcomes such as atrial fibrillation (AF), heart failure with preserved ejection fraction (HFpEF), and ischemic stroke. Although these outcomes are often treated as distinct clinical entities, emerging evidence suggests that they may represent symptomatic manifestations of an underlying atrial disease process. Aging promotes atrial myopathy through multiple mechanisms, including inflammation, extracellular matrix remodeling, electrophysiological alterations, cellular senescence, epigenetic modifications, and non-coding RNA regulation. These changes collectively lead to atrial fibrosis, impaired mechanical function, conduction abnormalities, and a prothrombotic state. Despite its clinical significance, atrial myopathy remains an underrecognized entity, with current management strategies primarily focusing on treating its downstream complications rather than the underlying disease. Advances in imaging techniques, biomarker discovery, and molecular research have the potential to improve the early detection and risk stratification of atrial myopathy, paving the way for novel therapeutic strategies. In this review, we discuss the structural, mechanical, electrophysiological, and metabolic changes that occur in the aging atrium, explore the cellular and molecular mechanisms that drive these changes, and highlight recent advances in diagnostic and therapeutic approaches. By shifting the focus from managing AF and HFpEF to targeting the underlying atrial myopathy, we can unlock new avenues for prevention and treatment, ultimately improving cardiovascular health in the aging population.