A case of swallow syncope induced by vagotonic visceral reflex resulting in atrioventricular node suppression.

A 48-year-old man repeatedly experienced syncope associated with paroxysmal atrioventricular block (PAVB) while swallowing. PAVB ("Mobitz type II" AH block) occurred only when "balloon-like" deformity of the lower esophagus developed. Balloon inflation in the lower esophagus induced PAVB. However, inflation in the upper or mid portion, or other vagal maneuvers, caused only sinus slowing. PAVB was not induced after intravenous atropine. The PAVB in this patient was probably caused by a vagotonic reflex triggered by tensoreceptors in the lower esophagus, resulting in selective suppression of the atrioventricular node.