Sudden Cardiac Death among Older Athletes
Updated: Jul 21, 2019
A practical guide about how to avoid suddenly dying while exercising
My father, Gordon, in his early 70's, died suddenly during his regular Sunday morning walk/run. He was about 20 meters into climbing a steep path when it happened. He was dead before he hit the ground. Looking back on it now, this was a good way for him to go, but it was untimely. He should have had at least another 20 years if only he had done some things differently.
Sudden cardiac death during exercise is rare and it is hard to identify common factors across all ages but there are some commonalities with older athletes that point to ways we can possibly reduce the risks a little, if not by a lot.
Although this article concentrates on older athletes, it is still relevant for the young ones.
(When I was studying sports medicine at the Otago School of Medicine, one of my major topics was "The Risks of Sudden Death During Exercise")
The following guidelines apply to all intense sports and exercise, but especially to those that have the tendency to start with a BANG! and sometimes stop that way as well.
What does medical research have to say about sudden cardiac death during exercise?
If you are into reading the technical stuff, please read this academic review, " Sudden Cardiac Death in Athletes" by Meagan M. Wasfy, M.D., Adolph M. Hutter, M.D., and Rory B. Weiner, M.D. :
Key Points that are taken from this review:
Though exercise is, in general, health-promoting, it is associated with an increased risk of sudden cardiac death for a small number of individuals who harbor cardiac conditions.
Sudden cardiac death is the most common medical cause of death in athletes, with an incidence of around 1 in 40,000 to 1 in 80,000 athletes per year according to the most recent estimates.
The risk and causes of sudden cardiac death vary based upon the athlete population. Male gender, black race, and basketball participation all place an athlete at higher risk. Sudden cardiac death in younger athletes (< 35 years) is commonly due to inherited cardiac conditions, while in older athletes (> 35 years) it is most often due to atherosclerotic coronary artery disease.
There remains significant debate over the best strategy to prevent sudden cardiac death in athletes and the role of the electrocardiogram in preparticipation screening. The optimal preparticipation evaluation for a given group of athletes depends on the risk of the population and available expert resources.
The authors also said: "There was no associated plaque rupture on angiography in any participants with CAD, suggesting that the SCA was due to supply/demand mismatch".
CAD = coronary artery disease. SCA = sudden cardiac arrest. SCD = sudden cardiac death
What we can take from this article are the following points:
SCD is rare and almost impossible to predict.
Preparticipation screening, other than for special groups, is of little benefit for the general population.
The most likely cause of SCD is insufficient blood supply to the heart to meet the dramatic increase in energy demands of the heart during intense exercise (a supply/demand mismatch). Hence the reason why the warm-up and starting a race advice I'm giving here is so very important for older athletes as a way of avoiding catastrophic supply/demand mismatch.
It is normal to prepare for these intense starts by doing a thorough warm-up but this is not always the case or possible. A paddler, cyclist or runner may thoroughly warm up only to end up waiting, stationary on the start line in the cold and wet, starting the race as good as without any warm-up.
As we get older a number of things happen deep within our bodies that increases the possibility of sudden death during exercise:
Plaque builds up inside our blood vessels. This is a like the scale that builds up in the water pipes of our houses. This is fatty and/or hard calcium. The rate that this builds up is influenced by the makeup of the blood, protective nutrients and the presence or absence of inflammation.
Tissues, especially the arteries, harden due to scarring and calcification. This process, along with laying down of plaque, is happening in at least 80% of people and begins early in life. Hard, scarred, partially blocked blood vessels, as well as muscles that more gristle than muscle due to chronic overwork and repeated injuries make it progressively harder to pump life-giving blood through the body.
Micro blood vessels become damaged and blocked. Tell-tale signs of this process, atherosclerosis and arteriosclerosis, may be seen as the development of tiny spider veins, which are most obvious around the insides of the ankles. When your optometrist looks at the back of your eyes, micro blood vessel die-off is being examined.
Systemic inflammation increases with age. The modern, globalised diet can be described as being "pro-inflammatory". Throw in toxins such as medications, arsenic, mercury, lead, herbicides, pesticides, illness and disease - infected gums for example - and excessive exercise - the inflammatory burden may be overwhelming.
Mineral and other nutrient imbalances and deficiencies get worse with age. Many minerals, principally calcium, magnesium, sodium, potassium and iron, and the fat and the water soluble vitamins, must all be plentiful and in balance for robust cardiovascular function.
Peak cardiovascular output declines by a factor of about 0.01 per year of life after the age of 28-30. This equates to about one heart beat less off your peak heart rate per year (this is where the 220 beats per minute - minus your age comes from to estimate your age-adjusted maximum heart rate). So, the typical 50 year-old athlete has around 20 or more fewer heartbeats to play with as compared to a 30 year old opponent. By 65 or 70 years of age the loss of peak cardiovascular capacity is huge and it shows in the performance.
The older athlete may be completely asymptomatic of any blood vessel blockages until the narrowing exceeds about 80% or more of a blood vessel's diameter. The only hint may be a faster than expected deterioration of physical work output and this is usually put down to "getting old".
As you read this you might have realised that all of the above are actually independent of and not the inevitable consequences of ageing. They are preventable, manageable and often reversible. Regardless of one's old age by the way.
The best measure of how well you are doing with this is your peak heart rate during exercise. If it is a little higher next year, despite you being a year older, then you are doing something right!
Reality check: The absence of symptoms does not necessarily mean the absence of disease. You may feel nothing at all but disease may be present, a bit like rust deep within your car chassis. All is well until you run over a pothole at speed one day and the wheels fall off. Bear in mind that medical tests for assessing cardiovascular risk during exercise may be no better than 30% effective in picking up anything that may be amiss.
Signs and symptoms of deteriorating cardiovascular health during exercise
For the sake of practicality, I'm restricting this section to what you, the athlete, can be assessing during exercise and rest, rather than including what may be measured in a medical or exercise physiology clinic.
These are most important for anyone who has a past history of cardiovascular disease, including atrial fibrillation, angina and heart attack. Bear in mind that first heart attacks are often silent and usually go undiagnosed, mistaken for a bout of indigestion or a chest muscle strain until the next and more catastrophic event hits.
Even if you have just been cleared by the cardiologist during your health-check which may have included an exercise stress test, please do not ignore any of the following:
Being unusually slow off the mark when the gun fires. Most older athletes know this one: the younger ones take off like crazy while the oldies gradually wind into the race, hoping later on to overtake those inexperienced youngsters who went out too fast. If you are much slower than usual in getting underway, take care!
Cramping in the lower legs and/or more frequent problems with calf strains. This may be more of an issue at the beginning of exercise and may diminish as one warms into it. The other symptom to be aware of is calf cramps that wake you during deep sleep.
Chest, arm, back and groin pain during exercise. This may come on as the pace quickens or when going up a hill and relieved by slowing down. The cause may be cardiovascular and not just mechanical.
Migraine-like head-ache during exercise. This may be muscular but may also be due to sky-rocketing blood pressure or an aneurysm.
Feeling spacey or even loss of consciousness during exercise. The cause may be low blood sugar but it could also be that the heart is failing and the blood supply to the brain is decreasing.
Irregular or racing pulse, or unusually slow pulse during exercise and/or while at rest.
Combine any of the above with a sense or feeling of distress and it is time to STOP! Lie down with your head and chest raised a little above your hips and prop the legs up a little as well. This position is the easiest on the heart by facilitating drainage of the legs and lungs. Get medical help. It is better to have some fuss made over you than to be dead. At the very least, slow right down, finish early, rest up and book in for a thorough medical examination.
Hints that circulation to the legs may be declining
Foot and ankle pain or outright injuries that appear to come on from nothing, are very slow to heal and may even fail to heal fully.
Discoloration of the skin overlying the shins, wounds that are slow to heal, varicose veins and spider veins. Your lower legs and feet are the points furthest away from your heart and lungs. If there is a significant loss of circulation, it will often first be seen in the feet. Easy injuring, poor healing, cramps and even deformed and fungal-infected toenails are indicators of deteriorating circulation to the legs.
Leg cramps that are suffered during deep sleep.
Why do people suddenly die shortly into intense exercise?
Think of sports like mountain biking, cyclocross, canoe and ski racing and many running races: the gun goes and there may be a frantic dash to get the best position. In these races a slow start can mean being caught in a massive traffic pile-up shortly into it so everybody starts at a crazy pace!
Have a look at the starts in the men's and women's races to get an idea of the intensity of the starts.
By the way, I'll be competing at the same Canadian venue this August to defend my age group title. It will be tough.
Squash used to be the headline sport for sudden death because it was popular with middle-aged males and usually began with little in the way of a warm up and typically finished suddenly when the time is up and the lights go out.
What do I think is going on.
The gun goes, everyone takes off like cats in fire, one drops dead shortly thereafter. What happened?
Blood is like gravy: when it is cold it is sticky, when it is warm, it flows freely.
Blood vessels constrict when cold and they dilate when warm.
Spare haemoglobin for oxygen transport and storage is liberated from the spleen several minutes into hard exercise. This release of extra blood into the circulation may be partly behind what is called "second wind".
If blood flow is compromised due to atherosclerosis. The heart must pump harder to get blood to the working muscles and there can be a lengthy time lag in getting a good flow of blood back to the heart. So the heart ends up working harder than ever to pump while the refilling of the heart between beats may be poor. This is why older athletes often find fast starts difficult to handle.
There is a sudden and massive increase in lactate. The buildup of lactate from maximal effort peaks between 5-10 minutes after the maximal effort of the fast start. If levels of lactate become too high this can become disabling. Muscles fail. The heart is a muscle and it can fail as well. The sudden and massive increase in effort within the heart muscle itself may mean the localised buildup of lactate may be faster and greater than what may be measured in the blood.
Sudden and violent cardiovascular effort may displace blood vessel debris, such as blood clots and plaque. This debris may then lodge in a narrowed blood vessel such as a coronary artery triggering blood clotting and a consequent heart attack. Stress and sitting still for long periods such as when flying or driving to an event may increase the risk of blood clots that may lead to deep vein thrombosis (DVT).
Imbalances and deficiencies in minerals (Mg, Ca, Na and K) may lead to electrical disturbances during extreme exercise. Think of the role of these minerals in preventing and alleviating muscle cramps. The hardest working muscle in your body is your heart and what do you think will happen if it goes into a cramp?
A special note about caffeine and similar drugs
In recent years there have been a number of sudden deaths in New Zealand during exercise involving the use of pre-workout supplements and caffeinated drinks. Asthma medications, antihistamines, caffeinated soft drinks, tea, coffee, "No Doze", pre-workout supplements and some headache medications may or do contain various forms of "speed" that may have the heart racing wildly, especially when combined, such as a pre-workout supplement that is washed down with a Red Bull drink. Any product that contains caffeine or any other stimulant needs to be ingested with care and in modest amounts, if at all. When combined with intense exercise these drugs can induce heart arrhythmia. A clue that the drug may be a stimulant equivalent to what is commonly referred to as "speed", is if the name finishes with "ine" on the end, such as caffeine, ephedrine, adrenaline, methamphetamine, nicotine, and many antihistamines. If you are not sure of what you are taking, look it up on the internet or leave it out, unless it is absolutely essential medically. Talk to your doctor about this if you are uncertain about what to do.
Guidelines for competing in a competition as an older athlete without inadvertently killing yourself
Ensure you have sufficient recovery between training sessions and between competitions. Do not go into an intense training session or competition in a state of exhaustion. Many athletes get into such a state of chronic exhaustion through habitual over-training and too much racing that they may know nothing else. If your muscles are weak and tired, the chances are that your heart is tired as well. Have 1-2 days of rest between hard training sessions and 2-4 days rest before a hard competition. Have 4-5 days of relative rest after a hard competition - ease back into training.
If travelling to a competition take these measures to avoid blood clots (deep vein thrombosis). https://www.garymoller.com/post/2016/04/21/how-to-prevent-deep-vein-thrombosis-dvt-in-athletes-and-traveling-sports-teams
Warm up thoroughly. Start warming up about half an hour or longer before the gun is anticipated. Wear warm clothing and gradually build up to an intensity that briefly replicates what is anticipated during the competition. If the weather is cold, make the warm-up longer and wear more clothing. If the weather is warm then the warm-up can be shorter. The fitter you are, the longer and more intense the warm-up can be. If you are unfit, be careful not to exhaust yourself during the warm-up. If you are preparing for a workout, and not a competition, your warm-up can simply be a graduated buildup of intensity during the workout and then winding down to "easy" over the final 10 minutes as a "cool-down".
Keep warm while waiting for the start and keep moving. You may notice that the pros in sports like mountain biking and cyclocross have stationary trainers that they remain on until the very moment that they are called to line up. While this may not be practical for you, keep warm and keep moving, even if that means jogging on the spot while waiting for the start. Wear extra clothing that you can toss to a supporter at the last moment. Some athletes will sometimes wear a rubbish bag or old clothing that can be discarded.
The warmer you are and the more you have been able to keep active up until the gun goes off, the faster and harder you can start. This may not always be easy since you may be corralled in with a hundred other eager athletes, all jostling for a good start position, so trying to keep moving may be impossible and attempts to do so may cost you a favourable start position. Do the best that you can and start slower if you have to.
Start slowly and gradually wind up the intensity. Apply smart tactics because nobody's heart appreciates a sudden and unexpected jolt into action. Let the young ones take off at a crazy pace, avoid the pile-ups as best you can then go as steady as possible to later reel in those who went out too fast.
Ease right off the pace if there is any hint of unusual distress and do not hesitate to stop. Live to fight another day. Intense competition hurts at the best of times. What we are talking about here are feelings of distress that are out of the ordinary, such as a dramatic loss of pace, spaciness, tunnel-vision, loss of balance, chest and arm pain. Remind yourself that this is only a game that you are participating in. Quit if you have to. Live to fight another day.
Race your own race - not other's. It is very easy to feel pressured to try to keep up with your main rivals. If they take off at the start like cats on fire, you must make the decision whether to go with them, or to hold back. Focus on yourself and not them, focus on how you feel and pace yourself wisely. Let them go, if you have to then gradually reel them back in later on
Gradually cool down after the competition. While you may sprint and collapse over the finish line, get up once you are able and move around for another 20-30 minutes. Keep active to flush the lactate out of the muscles and give the heart a chance to gradually slow down, rather than subject it to an abrupt cessation. Then go have a shower.
Consult your doctor. There is a time and a place to go and see your doctor and this is one of them. If you experienced any unusual distress, STOP and please see your doctor right away!
If you have a cold or influenza, should you be exercising?
Apply the NECK CHECK:
If the infection is above the neck and confined to the nose and throat, then you may exercise. But please bear in mind that sore throats usually mean that your body needs a rest, so take a few days off. At the very least, keep the intensity toned right down.
If the infection includes below your neck, do not do anything other than the mildest of exercise. If your body is infected, aching and feverish, you can assume that your heart is equally affected and distressed. Go home, go to bed. Rest!
Sudden Cardiac Death during sporting events is rare and mostly unpredictable. It can strike anyone ranging from those with Olympian fitness to the Weekend Warrior. Most of us know of someone who has died suddenly while exercising - I can think of several cases, including one former NZ running champion who, while recovering from the Flu, died suddenly at the end of an easy lunchtime run. He was in his early 50's. Bear in mind, though, that the most hazardous place to be for a heart attack is in bed and first thing in the morning after getting up and moving about. Exercise is safe and it can be made even safer by following these guidelines.
Exercise is good for you and good for your heart. Life is for living, and we never quite know when our number is up, so get out there and have a ball - make the most of the time you have but let's be sensible about the way we go about it.
The Risks of Sudden Death during Exercise: notes for a presentation on the topic by Gary Moller
blog.garymoller.com/2011/06/cardiovascular-disease-arteriosclerosis.htmlJun 29, 2011 - Cardiovascular Disease (Arteriosclerosis) Reversed - Here is the evidence!