By Douglas Main, Staff Writer
Published: 11/22/2013 08:43 AM EST on LiveScience
A healthy 20-year-old woman was running on a beach with friends when she fell on the wet sand. After briefly standing, she fell again, and within 30 seconds, became unresponsive. Her lips turned blue and she started gasping for breath. Her friends quickly called the paramedics and performed CPR, but it didn't help, according to a recent report of her case.
She was pronounced dead within half an hour. What happened?
According to the case report, the impact of the woman's body on the sand when she fell was enough to prompt a rare heart condition called commotio cordis, in which the heart is jolted into an arrhythmic pattern, after which it stops altogether. The report was published online Nov. 1 in the Journal of Forensic and Legal Medicine.
Commotio cordis is caused by an abrupt blow to the heart, usually by something small like a baseball, that strikes at a very specific time, said Dr. Emile Daoud, professor of internal medicine at the Ohio State University Medical Center, who was not involved in the woman's case. It typically strikes kids who have less muscle and fat than adults to shield their hearts. [9 Oddest Medical Cases]
The condition results from a blow during the brief period of time after the heart contracts, when the organ is recharging itself. During this time -- a span of a few milliseconds -- one part of the heart has repolarized and is ready to fire, while the rest of the organ is not yet ready. If an abrupt, focused blow strikes during this time, it can cause part of the heart to fire, but not the rest of it, Daoud said.
"This throws everything into chaos," Daoud told LiveScience. The heart goes into ventricular fibrillation, a name for the uncoordinated contraction of the ventricles (the lower chambers of the heart), and the patient usually dies from cardiac arrest.
Commotio cordis is quite rare, killing between two to four people yearly in the United States, according to the study. But once it strikes, it is deadly -- only about 10 percent of U.S. patients have been resuscitated and survived.
Due to its rarity, Daoud said he has not seen a case of commotio cordis, but has colleagues who have.
Dr. Suzanne Steinbaum, a preventive cardiologist at Lenox Hill Hospital in New York, has not seen patients with the condition and hasn't heard of colleagues seeing it, either, though she has read about it. "It's certainly scary -- these people are otherwise healthy with no underlying conditions," she told LiveScience.
But this case was even more unusual and rare than most. The patient was an adult, but the average age of people the condition strikes is 14. She was also overweight, whereas the condition tends to strike lean people -- it's thought that fat helps shield the heart from this type of blow, the researchers said.
Moreover, the woman fell on sand, which wouldn't be expected to cause this condition, Daoud said. Typically a very focused, hard impact is necessary, like a blow from a speeding baseball.
Even soccer balls and footballs have only rarely been found to lead to commotio cordis, Daoud added.