Complete Heart Block Related to Bicuspid Aortic Valve Calcification in a Triathlete.

BACKGROUND

While athletic patients may exhibit bradycardia, significant exertional symptoms in the setting of a bicuspid aortic valve (BAV) warrant further investigation.

CASE SUMMARY: A 36-year-old male triathlete presented with progressive exercise intolerance, fatigue, and bradycardia. Electrocardiogram demonstrated complete atrioventricular block (junctional ventricular escape: 52 beats/min). Echocardiography revealed a moderately calcified BAV with mild to moderate stenosis and preserved ventricular function. Cardiac imaging demonstrated a Sievers type 0 valve with asymmetric extravalvular calcification extending to the atrioventricular node and perimembranous septum near the penetrating His bundle, providing a mechanistic explanation for conduction block. A dual-chamber left bundle branch pacemaker was implanted, and the patient shortly returned to baseline performance.

DISCUSSION: This athlete's case highlights a rare presentation of complete heart block secondary to BAV-associated calcification, demonstrating its conduction implications.

TAKE-HOME MESSAGE: Bradycardia and decreased exercise tolerance in athletes warrant thorough evaluation for rare structural causes of conduction disease.