Electrocardiographic Alterations in Obstructive Sleep Apnea Syndrome: Mechanisms and Clinical Relevance.

Obstructive Sleep Apnea (OSA) is a highly prevalent yet frequently underdiagnosed disorder strongly associated with cardiovascular morbidity and mortality. It is characterized by recurrent episodes of intermittent hypoxia, intrathoracic pressure swings, and sleep fragmentation that trigger sympathetic hyperactivation, oxidative stress, systemic inflammation, and progressive structural cardiac remodeling. These mechanisms translate into a wide range of electrocardiographic (ECG) abnormalities, including both nocturnal brady- and tachyarrhythmias, as well as daytime conduction and repolarization changes. This narrative review synthesizes current knowledge on ECG manifestations of OSA, encompassing atrial and ventricular ECG characteristics and the burden of supraventricular and ventricular arrhythmias. Emerging evidence suggests that several daytime ECG markers may represent accessible, low-cost indicators of subclinical cardiac remodeling and autonomic imbalance, with potential clinical implications. In addition, there is a rapidly evolving landscape of artificial intelligence applications and wearable-based ECG monitoring for OSA detection and risk stratification. Standardization of ECG-derived markers, validation across diverse populations, and integration into clinical workflows represent key priorities for future research. Recognizing ECG alterations associated with OSA may support earlier diagnosis, improved arrhythmic risk stratification, and more effective multidisciplinary management.