Is syncope related to moderate altitude exposure?
OBJECTIVE
To investigate factors related to syncope occurring on recent ascent to moderate altitude.


METHODS
A 1-year retrospective case-control study, using local acclimatized residents as a control group.


METHODS
The two main ambulance destinations for Summit County, Colorado (elevation, 2770 m).


METHODS
All patients with a diagnosis of syncope, near-syncope, or fainting whose medical records were available for review.


RESULTS
There was a significant relationship (P less than .05) between syncope of unknown origin and recent arrival at altitude (less than 24 hours), and a significant inverse relationship (P less than .05) between syncope of unknown origin and arterial oxygen saturation as measured by pulse oximetry.


CONCLUSIONS
Short-term exposure to moderate altitude may be related to otherwise unexplained syncope in healthy young adults. We suggest the name high-altitude syncope for this entity and encourage further research in this area.
Nicholas
R
R
Colorado Altitude Research Institute, Snake River Health Services, Keystone 80435.
O'Meara
P D
PD
Calonge
N
N
D000064:Acclimatization; D000328:Adult; D000531:Altitude; D000704:Analysis of Variance; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D010100:Oxygen / Q000097:blood; D012189:Retrospective Studies; D013575:Syncope / Q000209:etiology*
D010100:Oxygen