Bayes Syndrome and Myocardial Fibrosis: Mechanistic Links and Clinical Implications.

Bayes syndrome is characterized by advanced interatrial block (A-IAB), which is associated with atrial fibrillation (AF) and ischemic stroke, and has gained widespread attention in recent years. Myocardial fibrosis, particularly atrial fibrosis, is a crucial substrate for the onset of AF and for atrial electricomechanical dysfunction. Growing evidence indicates a bidirectional relationship between Bayes syndrome and myocardial fibrosis. Myocardial fibrosis leads to delayed atrial conduction and the development of interatrial block (IAB), whereas IAB may exacerbate fibrosis through electrophysiological and hemodynamic changes. Several clinical studies have demonstrated that Bayes syndrome independently predicts the occurrence and recurrence of AF, ischemic stroke, and mortality. Imaging modalities, including late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) and echocardiography, enable noninvasive assessment of myocardial fibrotic burden and atrial structural and functional remodeling. Integrating electrocardiographic markers with imaging phenotypes may improve risk stratification, rhythm-monitoring strategies, and clinical decision-making. However, current evidence remains limited in terms of mechanistic elucidation and prospective clinical validation. This review synthesizes mechanistic and imaging evidence linking Bayes syndrome with fibrosis, discusses the clinical implications, and highlights potential targets for anti-fibrotic strategies and stroke prevention. This review also outlines key knowledge gaps and priorities for future longitudinal studies.