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Hartritme tijdens
en na inspanning indicatie voor kans op hartstilstand.*
Uit een uitgebreide
studie onder 5.700 deelnemers gedurende 23 jaar blijkt dat het hartritme tijdens
en na een standaard inspanningstest een voorbode kan zijn voor een mogelijke
hartstilstand, zelfs tientallen jaren later. Als tijdens de inspanning het
hartritme minder dan 89 slagen/minuut stijgt dan bestaat er een 6x grotere kans
op een hartstilstand. Als binnen een minuut na de inspanning het hartritme niet
met 25 gedaald is is die kans 2x groter dan in vergelijking met mensen waar dat
wel gebeurt.
Het merendeel van de
mensen kan deze problematiek oplossen door wat meer te bewegen waardoor het
hartritme wel voldoende stijgt bij inspanning en daarna weer snel zakt.
Voor de mensen die
door extra bewegen dit niet kunnen bereiken zouden medicijnen een uitkomst
kunnen zijn.
Heart Rate During and After Exercise Tied to Sudden Death
Slow response, slow recovery raises risk, a new study finds.
-- The way your heart speeds up when you exercise and returns to normal
when you stop can predict your risk of sudden death from heart attack, even decades
later, a new European study suggests.
Men whose heart rate increased less than 89 beats per minute during a
standard exercise test for heart patients -- called a stress test -- had six
times the risk of sudden death over the next two decades, said physicians in
France and Italy, who followed more than 5,700 middle-aged men for an average of
23 years.
Men whose heart rate
decreased less than 25 beats in the minute after they stopped the exercise test
had more than double the risk of sudden death than those whose rate returned to
normal faster.
The findings appear in the May 12 issue of the New England Journal of
Medicine
This is the latest chapter in a series of studies showing a relationship
between a higher risk of death from heart disease and the heart's
reaction to exercise, said Dr. Michael S. Lauer, a cardiologist at the Cleveland
Clinic Foundation who has done a lot of research on the subject. A paper by his
group published in 1999 in the same journal on a trial of 2,500 men was the
first to show the relationship between a slow return to a normal heart rate
after exercise and increased risk of death, Lauer said.
"We have since published a number of papers, and other groups have
published as well, all showing the same thing, that failure of the heart rate to
decrease quickly after exercise is associated with a higher risk of mortality,"
Lauer said. "What is unique and new about this paper is that it
specifically looked at sudden death, and most mortality in this group is
associated with sudden death.
"The second unique thing [about the new study] is the very long
follow-up," Lauer added. "It's pretty amazing when you think about it,
that a simple measurement on an exercise test can predict what will happen over
the next five, 10, 15 years. It's amazing that an old-fashioned, low-tech test
has this power."
The new results are "very similar and consistent" with those of
a study on men reported in 2003 by researchers at Johns Hopkins University, said
Dr. Roger S. Blumenthal, director of the Hopkins Preventive Cardiology Center.
"This really adds to the literature showing that abnormalities on a
stress test can show risk," Blumenthal said. "There is a growing body
of information looking at heart rate, not just length of time on the treadmill
or EKG changes."
The unanswered question now is how to put this information to use, Lauer
said. "We can identify people at increased risk for death, particularly
sudden death," he said. "Now we have to see how having this
information can translate into improved outcomes for patients."
There are two possible strategies that could be followed, he said. One is
the already well-known and often-promoted idea of regular exercise, which is
recommended for everyone but could have particular value for people with this
heart abnormality.
"People who exercise live longer because exercise stabilizes the
electrical system of the heart," Lauer said. "So we could take people
with these heart rate problems and enroll them in a formal exercise program that
would continue over the long term. My guess is that it would do an enormous
amount of good."
A second strategy might be drug therapy aimed at regulating the heart
rate, he said. "We have drugs which we used to correct heart rate problems,
mainly beta blockers," Lauer said. "They have been shown to improve
life expectancy."
A number of studies have shown that "exercise can improve autonomic
function and reduce the risk of sudden death," said Dr. William Whang, a
cardiac electrophysiology fellow at Massachusetts General Hospital.
Last week at the annual meeting of the Heart Rhythm Society, Whang
presented an analysis of data on more than 70,000 women in the Nurses' Health
Study showing that those who did little or no regular exercise had six times the
risk of sudden cardiac arrest than those who exercised for more than two hours a
week.
(Mei 2005)