Recent death of two Keystone skiers are a reminder of heart risks at altitude

Deepan Dutta
Summit Daily

This past week, twin tragedies took place within days of each other at Keystone Resort. Arvada resident Daniel Mares, 53, and Silverthorne resident Durwood Marshall, 66, died at Keystone while skiing during the Christmas holiday weekend. In both cases, Summit County Coroner Regan Wood determined that cardiac issues were the proximate cause of death.

While tree hits, fatal falls and avalanches are usually the biggest fears for skiers, cardiovascular problems are also a common — if more mundane — cause for sudden death on the slopes, especially among lowlanders. There were 23 cardiac-related deaths in Summit in 2016, with 19 coming up here from lower elevations and suffering cardiac issues soon after coming to altitude.

There has yet to be a definitive link established between altitude and cardiovascular death, as heart problems can be complex and multi-faceted with genetics and behavior playing big parts.

However, several studies have found a positive correlation between high altitude and cardiac death. An article published by the American College of Cardiology titled “High Altitude Exposure Among People With Cardiovascular Conditions” summarized a medical research study finding various factors that link cardiac death to altitude for people with pre-existing heart disease.

The main problem is the stress altitude puts on the body to deliver oxygen. Lower barometric pressure, temperature and humidity can confuse the body and put it in a mild state of panic. The body instinctively starts cranking up respiration in order to get healthy oxygen levels to the tissues. Akin to how an engine can overheat when trying to work too hard, the cardiovascular system can go into overdrive at altitude, especially if it is not used to the conditions.

Low pressure and low air density at altitude also means less oxygen is delivered to the body’s tissues. That, in turn, means less oxygen reaching the brain, known as “hypobaric hypoxia.” That affects everything from cognitive function to balance and control, which can be deadly while skiing.

The study found that the stress is more pronounced while the body tries to “acclimatize” to the conditions with a variety of physiological responses. For young, healthy individuals, the stress is not usually a problem and can be easily overcome.

However, for older individuals with pre-existing chronic heart disease, the increased stress the body is putting on the heart to deliver oxygenated blood can be too much for it to bear. The stresses are multiplied if the body has had no time to adjust to the conditions at altitude.

The combined effort of the body to stabilize oxygen levels makes existing cardiac problems much worse, increasing the likelihood of a fatal disorder such as a myocardial infarction, where a blockage occurs in the arteries supplying oxygenated blood to the heart itself.

The study laid out many of the things that older adults hear from their doctors and too often ignore: the heart is a muscle that beats non-stop our entire lives. When we get older, it gets weaker, more prone to disease and more prone to failure. While being at altitude isn’t guaranteed to kill you, it increases the risk. It does not pay to try to fight biology.

Suggestions that are offered to anyone coming up to ski at altitude include spending a comfortable amount of time at a lower elevation. That could mean spending a few nights in Denver if you’re from out of state, or at least staying in a resort community like Summit County overnight before attempting any strenuous activity. Trying to hit the slopes directly from the airport or even the Front Range without pausing to take a breath and letting the body catch up is a risky endeavor for anyone, not just the older among us.

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