Claudio Palma, 36, a San Francisco doctor who dressed as Elvis for Sunday's event, said he married his fiancee at the second mile of the marathon and stopped at the Burger Bar for a celebratory lunch, the Las Vegas Review-Journal reported Wednesday.
Palma said he was inside the eatery when a fellow marathon runner, a woman whose name Palma did not know, collapsed at the back of the restaurant.
The doctor said the woman was unconscious, had no pulse and was bleeding from the mouth and head. He said he got a quick medical history from the woman's husband and began to administer CPR.
Palma said the woman awoke to receiving mouth-to-mouth from Elvis.
"She was giving me a weird look and telling me she was OK," Palma said.
Paramedics arrived and took the woman to a hospital for further treatment.
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