I was of course, excited about the Men's Marathon trials yesterday in NYC. There has been a recent "come back" in American Long Distance running with several great runners up and coming.
Sadly, One of America's top runners, Ryan Shay surprisingly collasped and died 5.5 miles into the course yesterday. THis article explains that Shay had been diagnosed with an enlarged heart many years ago and had been cleared for athletic activity.
This sudden death of such a trained and accomplished athelete inspired me to look for more information regarding athletes and larger hearts.
I'm going to share a little bit of what I learned, which was very interesting to me, but may not be of interest to many others.
As atheletes become highly trained, some demonstrate changes in the Left Ventricle of the heart.
Medicos have termed this cardiac remodeling.
Some also demonstrate changes in the left atrium, but the Left Ventricular changes are it seems more significant.
If you look at the picture of the heart to the left, you can see that the left Ventricle is shown to be a little thicker than the right. The left Ventricle is considered the Main pumper, and pumps out the blood to the rest of your body. With sustained training it has been noted that the size of the left ventricle enlarges. allowing more blood to be pumped with each pump. This is why many atheletes have heart rates in the lower 40's and 50's. This phenomena applies to regular people as well as elite atheletes. My resting heart rate these days is about 52. In addition to an increase in size, for some atheketes the actual wall, or myocardium or the left ventricle gets thicker. This means to a certain extent that there is more muscle, and thus the heart can pump more powerfully. It can be noted that bigger is not always better, and after some time, getting larger, the left ventricle loses its elasticity and ability to pump well due to the thickened wall. Alheletes generally only have mild thickeneing. Here's a good picture example of increased Left Ventricle..
And another cross section of a real heart with
At the left
is an extreme
example and not one that would be shown in an elite athelete. An Elite athelete will actually have more muscle on the outside, rather than inside, as the above picture shows.
This graph shows that running is not the only sport to cause this phenomena. So, all you runners out there can now point to cyclists and swimmers as having a higher risk than runners!!
LV in the table stands for left ventricle.
It's nice to know that Yachting is a fairly safe sport, since it's one that so many of us can easily participate in !!
In general though, you might wonder, well…if the athletes conditioned heart can hold a little bit more blood and pump a little harder than a "normal" heart, whats the big deal? Why would that carry any major risk?
As it turns out, the athletic heart is somewhat more susceptible to arrhythmias. Most are harmless ones, a sler heart, or a slowed conduction of impulse to beat through the heart (from the atria to the ventricle). Some, however can be very dangerous and fatal. These are the tachyarrhythmias, which is generally the heart beating too fast.
A study of atheletes wearing a 24 hour Holter Monitor showed them to have significantly higer episodes of tachy arrhythmias. Most corrected on their own and were short lived. However, once a tachyarrhythmia starts there is no gaurentee that it will stop and return to a normal rhythm. In fact, the number one cause of sudden cardiac death for anyone in the US is Ventricular Fibrillation a fast and chaotic uncoordinated rhythm which is what all of those Automated Defibrillators are made to treat.
As it turns out, when these atheletes stopped peak training their risk for these arrhythmias decreased significantly as you can see in this graph below.
So, while no definite diagnosis has been put forth regarding Ryan Shay, I am surmising it is quite possible his heart, which was quite large, found its way into a tachyarrhythmia that it couldn't get out of.
My sincerest condolences to his family and friends. We have sadly lost a great contender.