Deglutition syncope and atrioventricular block selectively induced by hot food and liquid

Deglutition syncope is an uncommon disorder in which loss of consciousness follows swallowing. At least 26 cases have been reported. The cause appears to be an esophagocardiac vagal reflex producing atrial bradyarrhythmias or atrioventricular (AV) block.¹ Most cases have been associated with esophageal disease.² In some cases with no esophageal disease, a history consistent with esophageal spasm may be present.³ We recently encountered a patient in whom swallowing only hot substances could induce lightheadedness or syncope due to transient complete AV block.