Ice-cold beer–triggered swallow syncope with reproducible supra-Hisian AV block documented by intracardiac recordings

Introduction: Swallow syncope is a rare situational syncope caused by an exaggerated vagal reflex and may result in bradyarrhythmia or atrioventricular block. Methods: A 63-year-old man with recurrent syncope triggered by beer ingestion underwent cardiovascular, gastrointestinal, ambulatory electrocardiographic, and electrophysiological evaluation, including provocation testing. Results: Only ice-cold beer reproducibly induced transient AH block. Other foods and beverages, including cold soda, cold sake, and room-temperature beer, were negative. Ambulatory monitoring documented a symptomatic 7.9-second pause. Disopyramide was ineffective. Permanent pacemaker implantation prevented recurrent symptoms despite repeat provocation. Discussion: This case highlights a highly specific trigger for swallow syncope and the diagnostic value of targeted provocation testing.