The Hidden Shunt: An Asymptomatic Atrial Septal Defect Revealed by Echocardiography in a High-Performance Teenage Football Player.

Pre-participation cardiovascular evaluation aims to detect occult cardiac conditions that may increase the risk of sudden cardiac events in young athletes. Although echocardiography is not universally recommended for systematic screening, it can reveal silent congenital anomalies, particularly in highly trained individuals. In this report, we describe a case of a 14-year-old competitive football player with no prior medical history who underwent routine pre-participation evaluation. Clinical examination and resting electrocardiogram were normal. Transthoracic echocardiography (TTE), however, revealed an ostium secundum atrial septal defect (ASD) with mildly enlarged right chambers and a Qp/Qs ratio of 1.7, in the absence of pulmonary hypertension. Transesophageal echocardiography (TEE) confirmed adequate rims for device closure. Percutaneous occlusion using an ASD device was successfully performed without complications. Follow-up at one and three months confirmed appropriate device positioning and regression of right-heart dilation. This case highlights the potential role of echocardiography in uncovering silent congenital heart disease (CHD) in young athletes. Although routine TTE screening is not recommended for the general athletic population, selected high-level athletes may benefit from imaging to detect structural anomalies not identifiable clinically. The literature supports early identification and percutaneous treatment of significant ASDs to prevent long-term right-heart remodeling and adverse outcomes.