Syncope in the act of swallowing (swallowing syncope)

In a 30-year-old female patient with recurrent syncope during swallowing, intermittent complete AV-block was documented as the underlying mechanism. This phenomenon could be provoked by inflating a balloon positioned in the lower esophagus. The His-bundle electrocardiogram, recorded simultaneously, showed a progressive increase of the normal AH-interval, up to complete block distal to the A-wave. Atropine prevented induction of the block. After implantation of a VVI pacemaker, the symptoms disappeared completely. This very rare phenomenon of swallowing syncope is probably due to a pathologic vago-vagal reflex.