Will the real Phidippides Syndrome (if there is one ) please stand up

The legendary Greek courier who ran back and forth in the days surrounding the big battle between the Greek and the Persians in the fifth century BC was named Phidippides. The story goes that he first ran from Athens to Sparta carrying a request of the Athenians to the Spartans for aid and then ran back to Athens with the bad news that Sparta could not help, something about a religious holiday not allowing them to fight,running a total of 280 mile  round trip which took about 36 hours each way. That is about 3.8 mph or a 15.7 minute per mile pace- more of a brisk walk but the course was hilly. Then after the Athenians upset the Persians he ran from the site of the battle, the plains of marathon, to Athens to warn the city that the Persians  fled Marathon and were hoping to rush to Athens  by sea and attack again. This time Phidippdes was in a more of a  hurry and ran the 26 miles distance in about 3 hours or about a 7 minute per mile pace and died on arrival.

At least three different  clinical presentation have been deemed to be Phidippdes Syndrome (P syndrome)

James O' Keefe commented on the death of a legendary trail runner, Micah True AKA Caballo Blanco, who died on a run and at autopsy was said to have a dilated cardiomyopathy saying that this was an obvious case of P syndrome  if there were no other causes of a dilated cardiomyopathy and that P syndrome has some diagnostic,generally agreed upon differentiating features.

Dr. Justin Tivaxx reported a case of a 50 year old  half  marathon  runner who collapsed with and was resuscitated from ventricular fibrillation some 12 hours after a running workout. His MR showed a focal area of late gadolinium enhancement in the basal anterior septal said to not be a coronary artery distribution. This was suggested to be the focus of the previous ventricular fibrillation episode. Dr. Tivaxx presented in his paper an "hypothesis" concerning pathophysiology relevant to endurance exercise cardiac dysfunction and also said "considerable research is needed for to mature into an accepted understanding in clinical practice." Amen, yet some investigators write as if P. Syndrome is an accepted entity and that the general medical audience knows what it is.At the point I don't see how.

A third condition sometimes refers to as P syndrome is the putative clinical entity of exercise induced ARVD.At least two group of researchers  have presented some evidence that such an entity exists.



So what is P syndrome, a dilated cardiomyopathy in a endurance athlete, a runner with an area of delayed gadolinium uptake or  a person with ARVD who exercises.?