20 year old collapsed running marathon

20 year old collapsed during marathon .

According to the EMT report, "unconscious/down in street. Found altered, pale, SOB, speaking in 1-2 word sentences.  Pt. felt nausea enroute".  Vitals: BP 85/35 pulse 125, O2 sat 96%, sinus tachycardia, GCS 14. 1000cc NS given--GCS up to 15, BP 85/45, pulse 125.  After completion of saline--BP 101/65/ pulse 110. Pt .markedly improved on admission to ED.

Admitted to CCU, for three days with troponin levels of 5.47, peaked at 7.29 and dropped to 2.08.    Discharge Dx was:
1. Syncopal episode
2. MI, based on troponin levels and normal cardiac function based on follow up echocardiogram.
3. Marathon associated troponin leak of uncertain significance.
4. Acute renal failure, secondary to rhabdomyolysis, resolved
5. Hypophosphatemia and hypokalemia, resolved.
6. Acute dehydration.

Follow up cardiology studies done at a university medical center:   MRA, stress echo, both normal,  father refused the EP study.   Event monitor showed no arrhythmia even while running . Cardiologists recommended an implantable loop recorder.  I felt the loop recorder was very important as the syncope is still unexplained in full--the doctors think it may be a rare combination of the stress of the marathon, with severe muscle breakdown and very high CPK, and severe dehydration, but wanted to see the loop information over a year's time to rule out arrhythmia.

His father refused an internal loop recorder because it is invasive.  I think the more information we have, the better.  My son has declined the monitor.  He says that even if he were diagnosed with an arrhythmia, he would not use an ICD.  He has been cleared to run college cross-country. He runs like a gazelle.

Should I have been more assertive with his father and my son to understand how serious this is. The doctors were very clear in their explanations.   Please help me come to terms with this difficult dilemma.  Many thanks for your help.

[Cleveland Clinic]

This is a very complicated case, one which I think is very difficult to discuss without having the actual data. I understand that an arrhythmic cause of syncope has been sought so an implantable loop recorder ( which is a very small device) is a very effective way to diagnose malignant arrhythmias. Other tests may not be as sensitive such as MRIs or echos for the presence of structural heart disease. I don't know why he would have refused an EP study: the finding of inability to induce VT with PES is very important in ruling out VT as a cause of the syncope. But for ultimate protection an ICD could be implanted, but this seems premature at this time.
I think it is important to pursue an arrhythmic cause fully. Being more forceful with the father may be of some use. I understand this may have some effect on his ability to run competitively, but the upside here is we could be saving his son's life.