The priority is whether or not, throughout these lengthy minutes earlier than Mr. Hamlin’s coronary heart rhythm returned, when his coronary heart was not pumping usually, a scarcity of blood broken his mind, coronary heart consultants mentioned. If a affected person in cardiac arrest doesn’t get well instantly, medical doctors will typically induce a coma to provide the mind an opportunity to relaxation, Dr. Mack mentioned. Generally medical doctors additionally cool the mind to gradual its metabolism whereas it recovers, utilizing cooling blankets — which have coils that flow into chilled water — and headpieces.
“The extra concern there’s about mind damage, the extra aggressive medical doctors are about sedation and hypothermia,” Dr. Mack added. If Mr. Hamlin stays unconscious from 72 to 96 hours after his cardiac arrest, “there’s a actual concern,” Dr. Mack mentioned.
Different athletes, like marathoners, have collapsed and even died when their hearts stopped from coronary heart assaults or from arrhythmias brought on by underlying coronary heart abnormalities. Some examples, Dr. Mack mentioned, are hypertrophic cardiomyopathy, during which the center partitions are thickened, or lengthy QT syndrome, a heart-signaling dysfunction.
However, although they will’t rule them out, coronary heart consultants doubt that Mr. Hamlin has these circumstances. Dr. Rajat Deo, an arrhythmia specialist on the Perelman College of Drugs on the College of Pennsylvania, mentioned the N.F.L. extensively examined its athletes and could be anticipated to search out such issues.
Cardiac arrests differ from coronary heart assaults, that are induced when an artery supplying blood to the center is blocked, depriving the organ of blood. That may set off an arrhythmia and even sudden demise.
“May it have been resulting from a blockage?” requested Dr. Brahmajee Nallamothu, a professor of inside drugs and cardiology on the College of Michigan. “I suppose, however most likely unlikely in a younger man.”
Ken Belson contributed reporting.