Sudden cardiac death is a rare but devastating occurrence in marathons. Mandatory heart screenings, including history and physical examination, electrocardiograms (ECG), exercise stress testing and/or echocardiograms might decrease the 
incidence of these deaths. It is likely not feasible to ensure that every competitor in a race would undergo this testing.
One interesting idea would be to have runners wear electrocardiogram (ECG) monitors as they ran in the race. Combined with smartphones, the data could be sent through the cellular network to a station where a physician could interpret the tracings. If a runner exhibited ECG changes consistent with an arrhythmia, the doctor could alert emergency medical providers stationed across the race course and evaluate the runner before a cardiac event occurred.
Is continuous ECG monitoring feasible in marathons, though?
A study recently published in the European Journal of Preventive Cardiology tried this kind of monitoring in two marathons. Sebastian Spethmann and others found that this type of ECG surveillance showed promise, but there were some issues that must be worked out before it can be used on a widespread basis.
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Have an automated external defibrillator on site
Cellular networks must exist in every location along the route.
Since the ECG data would be sent via Bluetooth to the smartphone and from the phone to the medical center as a live feed, cellular networks would have to be accessible from all points on the course. While that task might not seem overwhelming, it could be difficult to ensure connectivity for all 26.2 miles.
The devices must be wearable.
In the model the researchers used, the runners wore both an ECG monitor and a smartphone on one arm. That might not sound cumbersome, but two large devices on one arm for over 26 miles could be a lot to expect most runners to wear.
A computerized screen for abnormalities needs to be built in.
If a physician in the medical tent had to analyze live ECG data, he could probably only watch a few runners. The race would then need hundreds of doctors in order to ensure that every runner’s heart monitor could be closely checked. Instead, the software would need to have some screening capabilities that alerted a physician to any abnormal ECG findings. The physician could then monitor the abnormal tracings of a much larger number of runners.
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Do you think continuous ECG monitoring is a good idea? If you run marathons, would you consider wearing these devices? How else can we monitor and prevent sudden cardiac deaths in marathons? Please share your ideas below!
Reference:
Spethmann S, Prescher S, Dreger H, Nettlau H, Baumann G, Knebel F, Koehler F. Electrocardiographic monitoring during marathon running: a proof of feasibility for a new telemedical approach. Eur J Prev Cardiol. 2014 Nov;21(2 Suppl):32-7.
