Atrial Septal Defect and Heart Rhythm Disorders: Physiopathological Linkage and Clinical Perspectives.

An atrial septal defect (ASD) is the most common congenital heart defect (CHD) diagnosed in adulthood. It is characterized by significant anatomical heterogeneity and complications that evolve over time. While often asymptomatic in children, the signs of adverse effects of ASD increase with age, including a greater risk of heart failure, stroke, atrial fibrillation (AF), and reduced life expectancy. ASD is traditionally considered a right-heart lesion due to long-term complications such as arrhythmias, right-sided heart failure, thromboembolism, and, in a subset of patients, pulmonary arterial hypertension (PAH). The pathophysiology of atrial shunts also affects the left heart due to volume overload and adverse ventriculo-ventricular interaction. Early diagnosis of interatrial septal anomalies is essential to prevent hemodynamic consequences and/or thromboembolic events. Electrocardiographic (ECG) findings play a crucial role in this early diagnosis. This narrative review aims to update clinicians on the latest evidence regarding the pathophysiological link between ASD and cardiac rhythm disorders, the nuances of optimal diagnostics, treatment options (surgical, interventional, pharmacological), and the need for long-term follow-up for patients with ASD. The review will determine the risk of conduction disorders compared to a healthy population and to compare the prevalences of conduction disorders, mortality, and pacemaker use in patients with closed ASDs versus those with open ASDs.