Autopsy shows ultrarunner had  idiopathic cardiomyopathy.

Micah True, also known as Caballo Blanco from “Born To Run Fame” , who died in March while running in the wilderness of New Mexico, was found to have idiopathic cardiomyopathy, or heart disease with an unknown cause, said the Office of the Medical Investigator.

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After appearing in Christopher McDougall’s best-selling book, True became an ultramarathoning legend. His popularity stemmed from spending months at a time in the Copper Canyon of New Mexico, where he befriended the Tarahumara tribe and started the Copper Canyon Ultramarathon. He was found dead on March 31. His body was found on the banks of a small stream with just his legs covered by water. He had been missing for days after heading out for a 12-mile run.

There were numerous abrasions on True’s extremities but no sign of internal injuries, the coroner said. The left side of his heart was found to be enlarged, and chemical tests showed that True was mildly dehydrated and also  revealed the presence of caffeine in his system. The autopsy report said the manner of True’s death was “natural.”

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