Monday Medical: A healthy heart at high altitude
February 19, 2018
If you're coming to the mountains from sea level, the change in elevation can do more than bring on a bout of altitude sickness: it can also impact your heart.
At higher elevations, the thinner air means each breath draws in fewer oxygen molecules. In Steamboat Springs, there are about 25 percent fewer oxygen molecules in the air than at sea level; at the top of Steamboat Ski Area, there are about a third less.
To get the oxygen it needs, your body has to work harder.
"Your lungs try to compensate by taking deeper and more rapid breaths, but they can't make up for the lack of oxygen," said Dr. Jason Jurva, a cardiologist with UCHealth Heart and Vascular Clinics in Steamboat Springs and Craig. "So, the heart has to beat faster."
To increase heart rate, adrenaline is released, which has side effects of its own, such as sleep interferences, high blood pressure and the feeling of a racing heart.
Though the body can acclimate to higher altitudes by beefing up its number of oxygen-carrying red blood cells, that process takes about three weeks.
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"If somebody's just arriving to town, they're going to have some limitations, especially in the first 48 hours," Jurva said. "People should understand they're not going to be able to do what they can at lower elevations."
Altitude can pose challenges for anyone with a heart condition. Even well-controlled heart issues, such as arrhythmias and chest discomfort, can become more noticeable with less effort.
Similarly, people who have heart muscle damage from a previous heart attack may feel fine at lower elevations, then find they are short of breath, retain fluid and have an increased heart rate at higher elevations.
And people who have been recently hospitalized with a heart condition are more at risk for having another incident at higher elevation.
To counteract the effects of elevation, Jurva recommends being in as good of shape as possible and taking it slow the first day or two.
"If I run into people on the mountain, and I hear they have a heart condition, I tell them to take it easy and not push it," Jurva said.
Eating a higher carb meal that first night can be helpful as it's easier for your body to digest.
And it's of top importance to stay hydrated. Drink plenty of water, even on the plane ride over, and limit dehydrating beverages such as alcohol and coffee.
"When you get dehydrated, the heart size actually shrinks, and with each beat of heart, you get less output," Jurva said. "When you hydrate, the heart is able to stretch more and with each beat you get more output."
Though it's common for people to feel their heart beat faster or their breathing become rapid when they first come to higher altitude, it's important to pay attention to symptoms.
"If someone starts experiencing any unusual shortness of breath, chest heaviness or a rapid sustained heart rate, they should first rest and try to get hydrated," Jurva said. "If symptoms don't resolve over the course of a couple minutes, they should seek medical attention."
People living at higher elevations can also feel the impacts of altitude, as chronic dehydration and sleep interferences can be more common. The thin, dry air makes it easier to lose water through everyday activities while hormonal shifts can cause night-waking and sleep apnea.
But over the longterm, altitude can be good for heart health.
"People living at elevation have a lower risk of heart disease than people at lower elevations," Jurva said. "That happens all over the world. So, it's not all bad."
Susan Cunningham writes for UCHealth Yampa Valley Medical Center. She can be reached at firstname.lastname@example.org.