Tuesday, November 13, 2007

6 Enlarged Heart = Cardiac Arrest? Improper cool down?

I sure don't want to sound like an alarmist, but hell, I was quite alarmed after reading news from an Olympic event some weeks back.

We all enjoy pain, training stress, body adaptation. We all at some point want to be like pro's on TV or glitzy-glossy bike magazines. This is a sport where pain and as much pain as possible is happily glorified through mass media.

And so we push ourselves. But the simple fact is that we're not pro's. We're mortals. And I've seen quite a number of folks who push themselves way too much. Think about it. Elite cyclists and runner have doctors for a reason (assuming dope doesn't exist). They have a free license to regular medical checkups. Since we aren't so privileged, is it time to rethink how much we push ourselves and how we condition our bodies for this pain? What is my point?

Endurance athletes who have years of training and racing in their belts have large hearts, this being a direct adaptation of training stress. Doctors have noticed this phenomenon for many years, and recently it was made famous after Lance Armstrong's Discovery Channel documentary.

Athletes' hearts hypertrophy to become larger, more powerful pumps over time, acquiring siginificantly higher stroke volumes per beat. The human body is simply marvellous. Essentially, with the higher stroke volume, the heart doesn't have to beat that fast and it can throw out the same output with a lower heart beat. They even have a lower resting pulse. Average humans have 70-75 bpm while athletes could have 50 or less. This, ofcourse, is a simplistic view of the adaptation and there is perhaps much more going on at the microscopic level.

The fact is kind of intuitive that as you stop stressing your body out that much, it can return to its past level. I'm not sure by how much. Would endurance athletes after a string of stressful seasons be able to get back to what they were before? Eddie Merckx and Hinault are probably doing very well these days.

Recent news of elite distance runner Ryan Shay collapsing and dying 4 or 5 miles into an Olympic marathon trials event has exposed the hazards of being an elite at the top of your game. I'm not sure how much percentage, but a certain number of elites develop what is known as ventricular arrhythmia (VA). Just google it out.

Studies have shown that most diagnosed (by birth of through endurance activity) with VA have dysfunctional right ventricles that could in the future lead to heart murmurs, irregular heart rythms which could result in sudden cardiac arrest. This is what may have happened with Ryan, but we dont know if its VA. We do know, as his doctors have said, that his death was caused by his enlarged heart.

With sudden cardiac arrest, the body's electrical system becomes defective and the heart is not able to form an organized beat and is plunged into rapid or chaotic activity.

Its probably a one or two in a 100,000 probability (or more, non lo so), but it sure is scary, and that's what happens when you push yourself way way too much. The scarier thing I've read about is this article from a Swedish Medical Center website that suggests that younger athletes have higher risk of cardiac arrest than collegiate and other older athletes. The article also suggests the importance of getting an electrocardiogram (EKG) checkup for young athletes but since this isn't very cost effective, other solutions are to teach young athletes about proper body conditioning for the sport, proper cooling down protocols after exertion and having pre competition checkups.
"Without a cool-down, the toxic wastes accumulate and may create such irritation and electrical instability that the heart will develop a fatal arrhythmia," he says

We live in a culture where being slim and hearty and healthy is just over emphasized. Not that many people follow it, since U.S has some of the highest percentages of obesity in the world, which is a fact. But the ones who aren't in this equation can also get trapped in a mindless, addictive world of over-fitness.. to gain acceptance, personal satisfaction or to win laurels for a team, school and perhaps state.

Perhaps it no reason to jump but its a relavant thought for today. If you're an amateur endurance athlete, how much are you pushing yourself and to what aim are you doing it? Are you stressed and tired, do you have little energy? How much do you know about your own heart? Have you ever had a screening or a checkup? Do you even care to go to a doctor or do you like to wait before its too late to turn back? Think about it. Fortunately, these conditions may be so rare we don't even have to worry about it. But my point is, an early diagnosis could save a life.


  1. There are 2 important points to consider when thinking about this.

    1) What is the incidence of sudden cardiac death in the normal population this age. You really don't hear about the non-unique 24 year old watching TV. It's the unique cases (Olympic athlete) that catches the media attention. Then there is always some anti-exercise people that attempt to make examples of why strenuous exercise is bad.

    2) Suppose these people all had some unknown/unidentifiable cardiac abnormality that would eventually kill them. Suppose exercise just caused it to appear at 25 and not 55. Once again we don't hear about the old man that drops.

    Heres a interesting article:

    or pubmed.com search sudden cardiac death

  2. Nate,

    I agree that incidences of sudden cardiac arrest is rare, but it still exists.

    But don't you feel many non-olympic athletes these days are pushing themselves way beyond... there are many folks who run, bike, lift, walk many miles. SOme do it without knowing how to train, some believe stretching is bad, some believe you get tougher by forcing yourself not to drink water and so on. These myths exist..

    So I feel heart muscle hypertrophy can happen in these individuals too. And if that can happen, and if there was some heart disease that was not detected, it could create complications. My article calls for checkups and a revision of the workload we give to ourselves. SOmetimes its just going to lead to danger. Too much of anything is bad. I don't say exercise is bad... I'm a staunch believer in the good things it has to give - low blood pressre, low LDL cholestrol, less chances of certain cancers, good muscular ability = less injury and so on..

    Btw, your first link led me to a porn site :)

  3. Some people may also believe that doing too much exercise is good for them which translates into not having to see the doctor. Well, its a fact that dysfunctions like heart dilation can co-exist with hypertrophy, which can be threatening to one's life.

    ANother thing to understand is that with stoppage or gradual decrease of intense exercise, heart may return to its normal size... so I'm not sure why RYan's doctors told him that he may require a pacemaker. But the article does say that he was diagnosed with an abnormality (not due to exercise) at age 14 or 15...who knows for sure.

  4. here is that link:
    I tried to be high tech

  5. that's pretty comprehensive. thanks i'll go through it when i get some time...

  6. Another figure, Spanish footballer Antonio Puerta, died this year of heart attack while playing on the field..


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