Claudio Palma tells the Las Vegas Review-Journal he was dressed as the King after Sunday's Las Vegas Rock 'n' Roll half-marathon when he performed CPR and resuscitated another runner at the Burger Bar at Mandalay Place.
The 36-year-old was clad in a jumpsuit, sideburns and scarf for the race and may have looked like Presley, but in real life, he's an anesthesiologist.
Palma says paramedics then arrived, and the woman gave him a weird look and told him she was OK.
He says the incident wasn't the only heart-stopping one that day: he also got married at a run-thru chapel during the race.