Glossopharyngeal insufflation induces cardioinhibitory syncope in apnea divers

Clin Auton Res. 2010 Dec;20(6):381-4. doi: 10.1007/s10286-010-0075-5. Epub 2010 Jul 11.


Apnea divers increase intrathoracic pressure voluntarily by taking a deep breath followed by glossopharyngeal insufflation. Because apnea divers sometimes experience hypotension and syncope during the maneuver, they may serve as a model to study the mechanisms of syncope. We recorded changes in hemodynamics and sympathetic vasomotor tone with microneurography during breath holding with glossopharyngeal insufflation. Five men became hypotensive and fainted during breath holding with glossopharyngeal insufflation within the first minute. In four divers, heart rate dropped suddenly to a minimum of 38 ± 4 beats/min. Therefore, cardioinhibitory syncope was more common than low cardiac output syncope.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Apnea / physiopathology*
  • Cardiac Output / physiology
  • Cardiography, Impedance
  • Diving / physiology*
  • Electrocardiography
  • Female
  • Glossopharyngeal Nerve / physiology*
  • Heart Rate / physiology
  • Humans
  • Hypotension / etiology
  • Hypotension / physiopathology
  • Insufflation*
  • Male
  • Oxygen / blood
  • Stroke Volume / physiology
  • Sympathetic Fibers, Postganglionic / physiology
  • Syncope / physiopathology*


  • Oxygen