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Swallow syncope associated with complete atrioventricular block and vasovagal syncope
H Kakuchi1, N Sato, Y Kawamura
1Asahikawa Medical College, First Department of Internal Medicine, Midorigaoka Higashi 2-1-1-1, Asahikawa, Hokkaido, 078 8510, Japan.
Heart (British Cardiac Society)
|May 18, 2000
Summary
Swallowing can trigger dangerous heart rhythm problems, like atrioventricular (AV) block, in rare cases. This study identifies an exaggerated vagal reflex from the esophagus as the likely cause of this unusual swallow syncope.
Area of Science:
- Cardiology
- Gastroenterology
- Autonomic Nervous System Function
Background:
- Recurrent atrioventricular (AV) block is a serious condition.
- Swallowing-induced syncope is an uncommon but recognized phenomenon.
Observation:
- A 21-year-old male experienced recurrent complete AV block episodes linked to swallowing carbonated beverages and esophageal balloon inflation.
- No underlying cardiac or esophageal pathology was identified.
- Atropine administration did not induce AV block.
Findings:
- Electrophysiological studies indicated AV block triggered by esophageal mechanical stimulation.
- A hypersensitive vagotonic reflex from esophageal mechanoreceptors was proposed as the mechanism, suppressing the AV node.
- Head-up tilt testing showed increased heart rate variability before syncope, suggesting heightened autonomic sensitivity.
Implications:
- This case highlights an unusual cause of syncope, emphasizing the role of exaggerated autonomic reflexes.
- Understanding these exaggerated reflexes is crucial for diagnosing and managing rare conditions like swallow syncope.
- Further research is needed to elucidate the mechanisms behind such hypersensitive autonomic responses.