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| File-This Jan. 4, 2008 file photo shows Cedars-Sinai Medical Center in Los Angeles. Sudden cardiac arrest may not always be so sudden: New research shows a lot of people ignore potentially life-saving warning signs in the days and weeks before they collapse. |
WASHINGTON
(AP) -- Sudden cardiac arrest may not always be so sudden: New
research suggests a lot of people may ignore potentially life-saving
warning signs hours, days, even a few weeks before they collapse.
Cardiac
arrest claims about 350,000 U.S. lives a year. It's not a heart attack,
but worse: The heart abruptly stops beating, its electrical activity
knocked out of rhythm. CPR can buy critical time, but so few patients
survive that it's been hard to tell if the longtime medical belief is
correct that it's a strike with little or no advance warning.
An
unusual study that has closely tracked sudden cardiac arrest in
Portland, Oregon, for over a decade got around that roadblock, using
interviews with witnesses, family and friends after patients collapse
and tracking down their medical records.
About
half of middle-aged patients for whom symptom information could be
found had experienced warning signs, mostly chest pain or shortness of
breath, in the month before suffering a cardiac arrest, researchers
reported Monday. The research offers the possibility of one day
preventing some cardiac arrests if doctors could figure out how to find
and treat the people most at risk.
"By the
time the 911 call is made, it's much too late for at least 90 percent of
people," said Dr. Sumeet Chugh of the Cedars-Sinai Heart Institute in
Los Angeles, who led the study reported in Annals of Internal Medicine.
"There's this window of opportunity that we really didn't know existed."
Importantly,
a fraction of patients considered their symptoms bad enough to call 911
before they collapsed, and they were most likely to survive.
That's
a reminder to the public not to ignore possible signs of heart trouble
in hopes they're just indigestion, said University of Pittsburgh
emergency medicine specialist Dr. Clifton Callaway, who wasn't involved
in Monday's study but praised it.
"Chest pain,
shortness of breath - those are things you should come in the middle of
the night to the emergency department and get checked out," said
Callaway, who chairs the American Heart Association's emergency care
committee. "We strongly recommend you don't try to ride it out at home."
Previous
heart attacks, coronary heart disease, and certain inherited disorders
that affect heartbeat all can increase the risk of sudden cardiac
arrest. People known to be at high risk may receive an implanted
defibrillator to shock the heart back into rhythm. But cardiac arrest is
such a public health problem that the Institute of Medicine last summer
urged a national campaign to teach CPR, so more bystanders know how to
help.
Monday's data from the Oregon Sudden
Unexpected Death Study examined records for nearly 1,100 people ages 35
to 65 who suffered a cardiac arrest between 2002 and 2012.
For
about a quarter of patients, researchers could find no information
about whether they experienced symptoms - making it impossible to say
just how common warning signs really are.
But
of the remaining 839 patients, half had evidence of at least one symptom
in the previous month, the study found. For most, the symptoms began
within 24 hours of their collapse, although some came a week before and a
few up to a month. Chest pain was most common in men, while women were
more likely to experience shortness of breath. Other symptoms included
fainting and heart palpitations.
Chugh had no
way to determine symptom severity. But only 19 percent of patients
called 911 about symptoms, mostly people with already diagnosed heart
disease or who were having recurrent symptoms. Their survival was 32
percent, compared with 6 percent for other patients. Partly that's
because a fifth of those 911 callers had their cardiac arrest in the
ambulance on the way to the hospital.
Stay
tuned: The study is just the start of more research to better predict
who is at highest risk for cardiac arrest, and determine how to target
them without panicking people who'd do fine with general heart disease
treatment, Chugh cautioned.
