FAQ: How Does High Altitude Affect Atrial Fibrillation?
Updated July 5, 2018: Two readers last week emailed me questions about hiking in mountains or living in a high altitude state like Colorado. They wanted to know: “Does research show if high altitude brings on A-Fib?”
High Altitude Affects Everyone
To begin, know that the lower oxygen environment of high altitude affects everyone, at least at first. Your body must make certain physiological adaptations. This is particularly obvious at very high altitude (9000+ feet). Oxygen levels are approximately 40%-45% less dense and feel like “thin air”.
Heart rate speeds up, increased adrenaline circulates in our bodies. The low moisture content in the atmosphere causes dehydration (50%-60% lower than at sea level).
Even healthy individuals often feel shortness of breath and fatigue.
How High Altitude Affects A-Fib
If physically active, conditioned and in shape, A-Fib patients without symptoms should generally be fine at high altitude (depending on concomitant other heart conditions).
For patients with episodes of atrial fibrillation, the stressors of high altitude may (or may not) be a trigger.
For those patients who have been cured of A-Fib, the risk of high altitude shouldn’t be much different from normal healthy persons.
Plan First with Your Doctor
When going to a high-altitude location, check with your doctor before hand. Your doctor may suggest that you rest and lower your normal activity level for several days after arriving at the high altitude.
In addition, it would be wise to have a plan for medication adjustment. For example, if on rate-control drugs, your doctor may want to up the dosage.
Adaption is the Key
For A-Fib patients, altitude and lower oxygen levels will affect your breathing and put a strain on your pulmonary veins where most A-Fib originates.
The key is gradual adaption. Before strenuous hiking or exercising in high altitude, allow at least a couple of days of lower than normal activity level.
To adjust to low moisture content and escape dehydration, hydrate well. Alcohol consumption should be minimized.
Also, watch for any new or unusual signs or symptoms of your a-Fib or of altitude sickness.
“High Altitude” and “Really High Altitude”
Reader comment: Michele Straube shared some insightful comments about high altitude and A-Fib. Michele Straube had A-Fib for 30 years until her successful ablation. She is an active hiker including walking the Alps.

Michele Straube
“There is “high altitude” and then there is “really high altitude”. Plus, even at “high altitude”, it is possible that anyone who has ever had A-Fib may feel some adverse effects. I offer two stories:
1. I was “cured” of A-Fib in 2009. In December 2015,, my family climbed Kilimanjaro taking a longer route up so we had time to acclimate. While the rest of the family summited, I stayed at base camp (15,580′) because my heart was no longer in NSR [normal sinus rhythm]. It returned to NSR as soon as we got down to 12,000′ elevation.
2. We do a lot of hiking in the mountains. Even though I’m not in A-Fib anymore, I feel the elevation (above 8,000′) more than most of my hiking companions. I don’t go into A-Fib (thank goodness), but my heart races and I often get dizzy. It takes me up to 5 days to acclimate, even at that not-so-high elevation.”
I admire Michele’s fearless attitude toward hiking and mountain climbing and her boldness in leading an A-Fib free life. Thanks, Michele, for sharing. To read Michele Straube’s story, go to ‘Cured after 30 years in A-Fib by Dr. Marrouche‘.



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Resources for this article
• Nunley, K. Heart Rate & High Altitudes. Sept. 11, 2017. Livestrong.com. https://www.livestrong.com/article/398387-techniques-for-running-breathing-in-high-altitude/
• Levine BD. Going High with Heart Disease: The ,of High Altitude Exposure in Older Individuals and Patients with Coronary Artery Disease. High Alt Med Biol. 2015 Jun;16(2):89-96. doi: 10.1089/ham.2015.0043. Epub 2015 May 21. PubMed PMID: 26060882.
• Altitude & the Heart. National Jewish Health. https://www.nationaljewish.org/conditions/cardiac-conditions/altitude-and-the-heart
• Raymond F. Stainback, MD. FAQ: Does high altitude have a negative effect on A-fib patients? Texas Heart Institute. 05/06/2016https://www.texasheart.org/heart-health/heart-information-center/frequently-asked-patient-questions/does-high-altitude-have-a-negative-effect-on-a-fib-patients/.