As we have some doctors in this group, and in any case, as healers, I am
forwarding the new information on heart attacks. It shows how extra oxygen can
paradoxically lead to cell death in an emergency. Also, I will recommend people
learn and remember the mudra that can help in case of heart attack:
To Treat the Dead
The new science of resuscitation is changing the way doctors
think about heart attacksand death itself.
|Ed Kashi / Corbis
Emergency: The goal is to give victims more
By Jerry Adler
May 7, 2007 issue - Consider someone who has just died of a heart attack.
His organs are intact, he hasn't lost blood. All that's happened is his heart
has stopped beatingthe definition of "clinical death"and his brain has shut
down to conserve oxygen. But what has actually died?
As recently as 1993, when Dr. Sherwin Nuland wrote the best seller "How We
Die," the conventional answer was that it was his cells that had died.
The patient couldn't be revived because the tissues of his brain and heart had
suffered irreversible damage from lack of oxygen. This process was understood to
begin after just four or five minutes. If the patient doesn't receive
cardiopulmonary resuscitation within that time, and if his heart can't be
restarted soon thereafter, he is unlikely to recover. That dogma went
unquestioned until researchers actually looked at oxygen-starved heart cells
under a microscope. What they saw amazed them, according to Dr. Lance Becker, an
authority on emergency medicine at the University of Pennsylvania. "After one
hour," he says, "we couldn't see evidence the cells had died. We thought we'd
done something wrong." In fact, cells cut off from their blood supply died only
But if the cells are still alive, why can't doctors revive someone who has
been dead for an hour? Because once the cells have been without oxygen for more
than five minutes, they die when their oxygen supply is resumed. It was
that "astounding" discovery, Becker says, that led him to his post as the
director of Penn's Center for Resuscitation Science, a newly created research
institute operating on one of medicine's newest frontiers: treating the
Biologists are still grappling with the implications of this new view of
cell deathnot passive extinguishment, like a candle flickering out when you
cover it with a glass, but an active biochemical event triggered by
"reperfusion," the resumption of oxygen supply. The research takes them
deep into the machinery of the cell, to the tiny membrane-enclosed structures
known as mitochondria where cellular fuel is oxidized to provide energy.
Mitochondria control the process known as apoptosis, the programmed death of
abnormal cells that is the body's primary defense against cancer. "It looks to
us," says Becker, "as if the cellular surveillance mechanism cannot tell the
difference between a cancer cell and a cell being reperfused with oxygen.
Something throws the switch that makes the cell die."
With this realization came another: that standard emergency-room procedure
has it exactly backward. When someone collapses on the street of cardiac arrest,
if he's lucky he will receive immediate CPR, maintaining circulation until he
can be revived in the hospital. But the rest will have gone 10 or 15 minutes or
more without a heartbeat by the time they reach the emergency department. And
then what happens? "We give them oxygen," Becker says. "We jolt the heart with
the paddles, we pump in epinephrine to force it to beat, so it's taking up more
oxygen." Blood-starved heart muscle is suddenly flooded with oxygen, precisely
the situation that leads to cell death. Instead, Becker says, we should aim to
reduce oxygen uptake, slow metabolism and adjust the blood chemistry for gradual
and safe reperfusion.
Researchers are still working out how best to do this. A study at four
hospitals, published last year by the University of California, showed a
remarkable rate of success in treating sudden cardiac arrest with an approach
that involved, among other things, a "cardioplegic" blood infusion to keep the
heart in a state of suspended animation. Patients were put on a heart-lung
bypass machine to maintain circulation to the brain until the heart could be
safely restarted. The study involved just 34 patients, but 80 percent of them
were discharged from the hospital alive. In one study of traditional methods,
the figure was about 15 percent.
Becker also endorses hypothermialowering body temperature from 37 to 33
degrees Celsiuswhich appears to slow the chemical reactions touched off by
reperfusion. He has developed an injectable slurry of salt and ice to cool the
blood quickly that he hopes to make part of the standard emergency-response kit.
"In an emergency department, you work like mad for half an hour on someone whose
heart stopped, and finally someone says, 'I don't think we're going to get this
guy back,' and then you just stop," Becker says. The body on the cart is dead,
but its trillions of cells are all still alive. Becker wants to resolve that
paradox in favor of life.