0
We're unable to sign you in at this time. Please try again in a few minutes.
Retry
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
Retry
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
ARTICLE |

High-Altitude Syncope: History Repeats Itself-Reply

Richard A. Nicholas, MD; Patrick D. O'Meara, DO
JAMA. 1993;269(5):587. doi:10.1001/jama.1993.03500050065016.
Text Size: A A A
Published online

In Reply.  —We are indebted to Dr Perrill for bringing to our attention the article by Henderson et al1 mentioning syncope at high altitude. The article, a fascinating series of studies regarding "the protection of aviators against the effects of high altitudes, low barometric pressure, and deficiency of oxygen," reports that several subjects had syncope or near syncope during hypobaric chamber studies simulating altitudes up to 10 500 m.An impressive 66% of subjects in their study had a fall in diastolic blood pressure. "In at least half of these the fall was sudden and great. It is always associated with fainting...." The fall in pressure was noted at oxygen levels as low as 14%, simulating an altitude of 3120 m. This was hypothesized to be secondary to "overcoming the vasomotor center by oxygen shortage." The authors note that subjects had varying responses to hypoxic stress and deduce that

Topics

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Figures

Tables

References

CME
Also Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Please click the checkbox indicating that you have read the full article in order to submit your answers.
Your answers have been saved for later.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.

Multimedia

Some tools below are only available to our subscribers or users with an online account.

25 Views
0 Citations

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Related Content

Customize your page view by dragging & repositioning the boxes below.

Jobs
×
brightcove.createExperiences();