At-home defibrillators: Proceed with
caution
By Linda Marsa, Times Staff Writer
The recent government approval of an at-home
defibrillator could reasonably be expected to save
lives. After all, 61 million Americans have heart disease
and most cardiac arrests happen at home.
But the device, which shocks a heart back into normal
rhythm, might do more harm than good, some experts
say.
"It hasn't been demonstrated that untrained family
members can use them effectively," said Dr. Vinay
Nadkarni, chairman of the emergency cardiovascular
care committee of the American Heart Assn. in Dallas.
And distracted family members may wait too long
before calling the paramedics.
"People may think just having the machine at home is
enough," said Nadkarni, and might not call 911
immediately. Each year, 250,000 people die of sudden cardiac arrest. Unlike a
heart attack, which cuts off blood flow to the muscle, cardiac arrest is triggered
by an erratic heartbeat that stops the heart from pumping. The only thing that can
restore the heart's natural rhythm is a jolt of electricity, known as defibrillation.
The window for successful resuscitation is 10 to 12 minutes, and for every
minute of delay, chances of survival drop by 10%. Since it can take six minutes
or more for paramedics to respond to 911 calls, an external defibrillator can
provide treatment before they arrive.
There's been a widespread drive to place these life-saving devices not only in
ambulances, firetrucks and police cars, but in airports, planes, stadiums, health
clubs, shopping malls and schools. But 70% of cardiac arrests occur at home,
which is why the devices have been adapted for home use. The Food and Drug
Administration earlier this month approved the first such device, Philips
Electronics' HeartStart Home Defibrillator, which will be available with a
prescription.
Twenty years ago, only physicians used defibrillators, but advances in technology
have made it possible for someone with no medical expertise to use them. Unlike
older devices, which required a doctor to determine heart rhythm, the new
models are programmed to detect irregularities. "That's the key change that
makes it possible to use them at home," said Dr. L. Bing Liem, an
electrophysiologist at Stanford University School of Medicine in Palo Alto.
Last month, a New England Journal of Medicine study of defibrillator use at
three Chicago airports found that untrained people can indeed save lives.
HeartStart, which was tested for ease of use by a group of sixth-graders, walks
people through the resuscitation process. Once users pull back the handle, they
are given step-by-step voice instructions, accompanied by written directions on
where to place the paddles. "If you need extra help, it will pause with you and
provide coaching comments," said David M. Freeman, a vice president with
Philips Electronics in Andover, Mass.
The system does weekly self-checks, and chirps like a smoke detector if the
battery runs down. Users can't zap someone accidentally--the device is
programmed to detect rhythms and will only jolt hearts that need it.
Although sudden cardiac arrest can strike people at any age, the most likely
victims are men in their 60s, which means the defibrillator will be most often used
by their wives or someone else living in their home.
But even though the device has been tested on sixth-graders, Nadkarni said,
"sixth-graders are not the spouses of sick patients, and we don't know how
people will act in a true emergency situation."
Furthermore, the $2,295 cost for the HeartStart Home Defibrillator may be
prohibitive for retirees on a fixed income, since it's unclear whether insurers or
Medicare will pay for them
The National Institutes of Health is beginning a study to determine if these
at-home devices increase survival rates among people at high risk of cardiac
arrest. But results won't be known for four years. In the meantime, says
Nadkarni, family members who want the device should get proper training from
their local Red Cross.
CVS pharmacy, a major drugstore chain in many parts of the country, is
expected to stock the machines in about six weeks; in California, they can be
ordered via the Internet at www.heart starthome.com.
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