What We Do and Don’t Know About Damar Hamlin’s Cardiac Arrest - The New York Times

A freakish mishap whitethorn explicate the origin of the cardiac apprehension that sent Damar Hamlin of the Buffalo Bills to the crushed during a shot crippled connected Monday night, 5 cardiac experts said.

It is not yet known wherefore Mr. Hamlin’s bosom stopped astir 9 minutes into the crippled against the Cincinnati Bengals. But his youth, wellness and different circumstances could mean that a stroke to his thorax during a collision with a receiver connected the opposing squad sent his bosom into an erratic bushed known arsenic an arrhythmia.

Dr. Aaron Baggish, a sports cardiologist astatine Harvard Medical School who has worked with the New England Patriots, cautions that, portion a stroke to the thorax “is decidedly a front-runner” to explicate what occurred connected Monday, “it is premature to beryllium definite.” Mr. Hamlin, helium said, volition astir apt acquisition extended investigating to beryllium definite determination was nary different cause.

For an arrhythmia to occur, determination has to beryllium what Dr. Baggish called “a cleanable storm” — the thorax indispensable beryllium struck successful a precise spot astatine a precise infinitesimal portion the bosom is relaxing aft squeezing retired blood, and with the close magnitude of force.

“It’s not rare, but it’s beauteous unusual,” said Dr. Michael Mack, the president of cardiovascular services astatine Baylor Scott & White Health successful Dallas. Most documented incidents person occurred successful shot erstwhile a subordinate has been struck successful the thorax by a ball, and it has besides occurred successful lacrosse and hockey. Chest protectors did not forestall the incidents.

There is conscionable a 20-millisecond interval successful the heart’s rhythm erstwhile a beardown stroke tin origin an arrhythmia, said Dr. Javid Moslehi, a cardiologist astatine the University of California San Francisco School of Medicine.

Shortly aft Mr. Hamlin, 24, collapsed, aesculapian unit astatine the crippled administered cardiopulmonary resuscitation for 9 minutes arsenic they tried to support humor moving done his body. When his bosom bushed was restored, they took Mr. Hamlin to the University of Cincinnati Medical Center, wherever helium remains successful captious condition.

It is mean to enactment patients similar Mr. Hamlin connected a respirator, Dr. Mack said. But, helium added, “if helium is inactive connected the respirator today, that means helium has not awakened.”

The interest is whether, during those agelong minutes earlier Mr. Hamlin’s bosom bushed returned, erstwhile his bosom was not pumping normally, a deficiency of humor damaged his brain, bosom experts said. If a diligent successful cardiac apprehension does not retrieve close away, doctors volition often induce a coma to springiness the encephalon a accidental to rest, Dr. Mack said. Sometimes doctors besides chill the encephalon to dilatory its metabolism portion it recovers, utilizing cooling blankets — which person coils that circulate chilled h2o — and headpieces.

“The much interest determination is astir encephalon injury, the much assertive doctors are astir sedation and hypothermia,” Dr. Mack added. If Mr. Hamlin remains unconscious from 72 to 96 hours aft his cardiac arrest, “there is simply a existent concern,” Dr. Mack said.

Other athletes, similar marathoners, person collapsed and adjacent died erstwhile their hearts stopped from bosom attacks oregon from arrhythmias caused by underlying bosom abnormalities. Some examples, Dr. Mack said, are hypertrophic cardiomyopathy, successful which the bosom walls are thickened, oregon agelong QT syndrome, a heart-signaling disorder.

But, though they can’t regularisation them out, bosom experts uncertainty that Mr. Hamlin has these conditions. Dr. Rajat Deo, an arrhythmia specializer astatine the Perelman School of Medicine astatine the University of Pennsylvania, said the N.F.L. extensively tested its athletes and would beryllium expected to find specified problems.

Cardiac arrests disagree from bosom attacks, which are caused erstwhile an artery supplying humor to the bosom is blocked, depriving the organ of blood. That tin trigger an arrhythmia oregon adjacent abrupt death.

“Could it person been owed to a blockage?” asked Dr. Brahmajee Nallamothu, a prof of interior medicine and cardiology astatine the University of Michigan. “I guess, but astir apt improbable successful a young guy.”

Ken Belson contributed reporting.