Glossopharyngeal insufflation induces cardioinhibitory syncope in apnea divers.
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.
Dzamonja
Gordan
G
Department of Neurology, Clinical Hospital Split, Split, Croatia.
Tank
Jens
J
Heusser
Karsten
K
Palada
Ivan
I
Valic
Zoran
Z
Bakovic
Darija
D
Obad
Ante
A
Ivancev
Vladimir
V
Breskovic
Toni
T
Diedrich
André
A
Luft
Friedrich C
FC
Dujic
Zeljko
Z
Jordan
Jens
J
D000328:Adult; D001049:Apnea / Q000503:physiopathology*; D002302:Cardiac Output / Q000502:physiology; D002307:Cardiography, Impedance; D004242:Diving / Q000502:physiology*; D004562:Electrocardiography; D005260:Female; D005930:Glossopharyngeal Nerve / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007022:Hypotension / Q000209:etiology / Q000503:physiopathology; D007327:Insufflation; D008297:Male; D010100:Oxygen / Q000097:blood; D013318:Stroke Volume / Q000502:physiology; D017779:Sympathetic Fibers, Postganglionic / Q000502:physiology; D013575:Syncope / Q000503:physiopathology*
D010100:Oxygen