Sign-in to Ask A Doctor - 24x7
OR
Sign in with Google
What Causes Sudden Loss Of Consciousness, Low BP And Low Pulse Rate?
Posted on
Sat, 30 Jul 2016
Medically reviewed by
Ask A Doctor - 24x7 Medical Review Team
Sat, 30 Jul 2016
Answered on
Mon, 22 Aug 2016
Last reviewed on
Question : My son in law suffered went unconscious , half an hour into a flight from Majorca Spain to XXXXXXX uk , just before he went unconscious he was shaking, had a very low blood pressure , with a pulse of 50.
Normally a very fit man ,and runs every day, very slim. Have you any idea of what might have caused it, we have been in 35 degree temperatures for two weeks.
Normally a very fit man ,and runs every day, very slim. Have you any idea of what might have caused it, we have been in 35 degree temperatures for two weeks.
Brief Answer:
Read below.
Detailed Answer:
I read your question carefully and I understand your concern.
Judging from your description of low blood pressure and slow pulse the most probable cause for the loss of consciousness seems to be insufficient blood supply to the brain, a syncope. It does not seem to be a seizure, not something directly related to the brain (such as stroke, tumor etc).
The most common cause for his syncope is a vasovagal response, an inadequate response of the vagus nerve which acts by slowing heart rate and lowering blood pressure. Usually it is in the setting of some strong emotion, fear, stress, but also physical exertion, dehydration etc. Vasovagal syncope is benign and doesn't usually require any treatment. When there is a clear precipitating event no further tests are necessary either.
Since in your son in law's case though you do not describe any such triggering factor (unless he has anxiety from flying) some tests for other syncope causes are recommended. By such tests I mean at least an EKG and some routine blood tests (blood count, glucose, electrolyte panel) to screen for anemia, infections, electrolyte alterations.
If those result normal one might want to push further with a heart ultrasound and 24hour Holter EKG recording to check for issues with heart valves, transitory arrhythmia etc, but I would go ahead with them only if there are repeated episodes, for one single event in a healthy young man I would leave it at that.
I remain at your disposal for other questions.
Read below.
Detailed Answer:
I read your question carefully and I understand your concern.
Judging from your description of low blood pressure and slow pulse the most probable cause for the loss of consciousness seems to be insufficient blood supply to the brain, a syncope. It does not seem to be a seizure, not something directly related to the brain (such as stroke, tumor etc).
The most common cause for his syncope is a vasovagal response, an inadequate response of the vagus nerve which acts by slowing heart rate and lowering blood pressure. Usually it is in the setting of some strong emotion, fear, stress, but also physical exertion, dehydration etc. Vasovagal syncope is benign and doesn't usually require any treatment. When there is a clear precipitating event no further tests are necessary either.
Since in your son in law's case though you do not describe any such triggering factor (unless he has anxiety from flying) some tests for other syncope causes are recommended. By such tests I mean at least an EKG and some routine blood tests (blood count, glucose, electrolyte panel) to screen for anemia, infections, electrolyte alterations.
If those result normal one might want to push further with a heart ultrasound and 24hour Holter EKG recording to check for issues with heart valves, transitory arrhythmia etc, but I would go ahead with them only if there are repeated episodes, for one single event in a healthy young man I would leave it at that.
I remain at your disposal for other questions.
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Answered by
Get personalised answers from verified doctor in minutes across 80+ specialties
