CONTACT: TOM MOORE
Joint Office for Planning, Marketing and Communications
8788 John Pappajohn Pavilion
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Release: March 21, 2002
UI researchers part of national implantable defibrillator study
of Iowa Heart Care researchers participated in a landmark national study that
found that patients left with weakened hearts following a heart attack who
receive an implantable cardioverter defibrillator (ICD) are 30 percent more
likely to still be alive two years later than patients without ICDs.
study was called the Multi-center Autonomic Defibrillator Implantation Trial,
or MADIT II. Some1,232 patients were enrolled at 76 advanced heart centers
nationwide over a four-year period. All of the patients had survived heart
attacks that caused moderate left ventricular dysfunction, meaning that their
hearts' ability to pump blood was reduced. One group was randomly assigned
to receive an ICD, the other group received the best available conventional
years, the patients who had ICDs were almost one-third more likely to still
be living than patients in the other group. That pattern continued through
the next four years. The dramatic results led the study's independent data
and safety monitoring board to stop the study earlier than planned.
MADIT II trial will revolutionize the way we care for such patients following
a heart attack," said UI professor of internal medicine Brian Olshansky,
M.D., a specialist in electrophysiology with UI Heart Care and an investigator
involved with the study. "It's very exciting to know that we can so significantly
improve survival with this advanced technology."
An ICD helps
restore a normal heart rhythm in three ways, including anti-tachycardia pacing,
or delivering a series of small electrical impulses to restore a normal heart
rate and rhythm; cardioversion, or delivering a low-energy electrical shock
at the same time to restore a normal heart rhythm; and defibrillation, which
is the delivery of a high energy shock to the heart muscle to restore a normal
rhythm. Vice President Dick Cheney is currently benefiting from an ICD.
– about 250,000 – die every year in the United States from serious,
fast heart rhythms than from any other cause. ICDs have the ability to rescue
patients from these heart rhythms.
knew that ICDs worked very well in other patient populations, such as children
with a high risk for sudden cardiac death," Olshansky said. "Now
we have clear proof that patients who have a heart attack that leaves them
with a heart that doesn’t pump blood properly will also live longer
if they too receive an ICD."
An ICD is
about the size of a pager. The device is implanted under the skin of the upper
torso, with wires that carry electrical energy to the heart. The ICD constantly
monitors the heart's rhythm. When it detects a very fast, abnormal heart rhythm,
it delivers the appropriate electrical energy to the heart muscle to cause
the heart to beat in a normal rhythm again.
University of Iowa Health Care describes the partnership between the Roy J. and Lucille A. Carver College
of Medicine at the UI and the UI Hospitals and Clinics and the patient care,
medical education and research programs and services they provide. Visit UI
Health Care online at www.uihealthcare.com.