The official word is:

The Heart at High Altitudes

Ascent to moderate altitude appears to entail little risk for travelers with coronary artery disease who are ordinarily asymptomatic or who have moderate exercise tolerance. They may develop angina at a lower level of exertion, but generally have no impairment of their ability to acclimatize. They should rest for a few days after arrival at altitude, and ascend slowly thereafter. If the traveler is on treatment for angina, atrial fibrillation, hypertension, or mild compensated congestive heart failure their medications should be carefully adjusted, especially to keep the blood pressure and pulse well controlled.

However, the question that many people (and their doctors) ask about high-altitude travel is will it trigger a heart attack? or Is there a risk of sudden death? Younger people need not worry about this, but what if youre a 50-year-old man in relatively poor physical condition, perhaps with several cardiovascular risk factors? Is trekking a good idea? Reports in the medical literature demonstrate an increased incidence of sudden cardiac death associated with abrupt exercise in sedentary people, but there are little data about the risk during participation in mountain sports.

In a report of sudden deaths among high mountain hikers and skiers in Austria, hikers were more than twice as likely to die as skiers. Among the hikers, the risk of death was highly associated with an age of more than 40 years and lack of prior physical activity. In contrast, a study of medical evacuations of climbers and trekkers in Nepal showed that cardiac disease accounted for only 5% of the evacuations, and none of the deaths. One reason for this difference could be that the climbers that went to Nepal were in much better physical condition.

The possibility of an acute cardiac event has prompted efforts to screen asymptomatic travelers in an effort to identify the presence of coronary disease before the occurrence of a serious problem. A stress test is often recommended. Unfortunately, exercise stress tests have limited effectiveness because they dont show the anatomy of the coronary arteries. They miss plaques that are not large enough to obstruct blood flow, but that have the potential to destabilize and rupture, causing new-onset angina, heart attack, or cardiac arrest. More sensitive tests are needed to detect these asymptomatic plaques, and if found, to stabilize them.

Ascending slowly is the best way to avoid altitude sickness.[4] Avoiding strenuous activity such as skiing, hiking, etc. in the first 24 hours at high altitude reduces the symptoms of AMS. As alcohol tends to cause dehydration, which exacerbates AMS, avoiding alcohol consumption in the first 24-hours at a higher altitude is optimal.

My experience is that over 8,000 feet, everyone has some breathing adjustments/difficulties for a couple of weeks. Even 5,000 feet in places like Denver can be noticeable. BTW, airplane cabin pressure is kept around 8,.

Probably the best advice is to discuss the below with your EP:

For those with arrhythmias, rapid ascent to altitude might result in faster heart rates in patients with atrial fibrillation or flutter, so patients should be advised to consider increasing doses of beta blockers, for example, say Higgins et al. And although there is a theoretical risk of increased ventricular arrhythmias based on increased sympathetic tone, this "does not appear to be clinically relevant," they observe.

And in patients with congenital heart disease with shunts, exposure to high altitude "should be avoided," the researchers caution, because of the "potential catastrophic effects of an acute increase in left-to-right shunting and/or pulmonary artery pressures." But exposure to moderate altitude has been reported to be safe even in those with cyanotic congenital heart disease, they note.


petey

8000 feet for cabin pressure (edit)

I travel over Douglas Pass and it a bit over 8000 and am fine. But I would ask your doctor. Mine told moving from lower was okay. I was to Silverton and Durango and down there okay. I really not sure how high I have been up. But you go from low area to high area you should feel it and any one would. I rode the steam train at Drango to Sliverton. Before Afib yes I would feel 11,000 up around Leadville.

When I left the hospital 2 years ago I asked if moving higher would hurt me. No. I am living not quite a 1000 ft higher than was. My lungs are fine but air is thinner to breathe when you get up high. What Petey says. I am 80. My B/P is normally on low side. I sure was not told to not go up high. But it is best to ask and be safe.

Death Valley is more than 200 feet below sea level, if you want a low altitude vacation.

I had a problem at the Grand Canyon. 8000ft.... and that was before I even knew I had afib.

Same with me on the way to Old faithful (prior to AFIB discovery) going through the continental divide at 8640 feet.

petey

Thank you petey, Colorado and island for you comments. They are very helpful.

Have great time Steve!

I have not experienced any problem with altitude and my afib at all.

We go from Phx (1200 ft elevation) to Flagstaff (7200 ft elevation) with no problem. Even, I hiked up the San Francisco Peak in Flagstaff to 13,600 ft without any problem. At the top, I felt fine. However, during the climb, I would get dizzy and felt nausea after 10,000 ft if we went too fast. Eevery 10 minutes, we had to stop for 5 minute to let our body adjust.

Also, in Maui (Hawaii), we went to Mount Haleakala (10,000 ft) for a hike. Well, when we got to trail head, we were very sick, severe headache and nausea since we went from sea level to 10000 ft in 45 minutes by car. So, we waited for one hour before we started our hike into the volcanos. This is a MUST do hike since the landscape looks like moon surface, almost no vegetation and mostly black. You must take winter clothing for this hike, the temprature is about 40 with constant rain, sleet, and high winds with breif clearings.

Bottom line, altitude appears to have no effect on the afib but it can cause headache and dizziness until you get acclimated.

Scott

Steve, have fun in New Mexico!

I have a second home in Santa Fe. I admit I often have a flare-up of symptoms when I go there. It is best, but often unrealistic, to do it slowly (ie- stay in Albuquerque a few days) I have been told that it takes about 2 weeks for the body to adjust to higher altitude, but I am usually not there that much.

I have once had to go to the ER but I would advise using Albuquerque. There are cardiologists in SF but the ones I've seen I didn't feel comfortable with. Also if they are not EP's they tend to minimize Afib and tend to concentrate more on regular heart disease.

But the general advice is to take it slow, drink lots of water, little alcohol, and stay calm.