found that patients who received the implantable device
and had it turned on could walk further distances, felt
better, had fewer hospitalizations, and a decreased
need for intravenous medications.”
Abraham, M.D., co-director of the Linda and Jack Gill
13, 2002 (Lexington, Ky.) A
study of cardiac resynchronization in chronic heart
failure patients led by William Abraham, M.D., co-director
of the Linda and
Jack Gill Heart Institute at the University of Kentucky,
indicates significant clinical improvement in patients,
according to an article released in the June 13 issue
of The New England
Journal of Medicine.
Cardiac resynchronization therapy is a new treatment
for heart failure that uses an implantable device, the
Medtronic InSync® cardiac resynchronization system, to improve the pumping
efficiency of the heart.
“We found that patients who received the implantable
device and had it turned on could walk further distances,
felt better, had fewer hospitalizations, and a decreased
need for intravenous medications,” Abraham said about
the multi-center study.
Nearly 600 patients at 45 centers participated in
the study, which was conducted between November 1998
and December 2000. About 60 of these patients were
enrolled in the study under the care of Abraham.
The InSync® device with specialized leads,
which was approved by the U.S.
Food and Drug Administration in August 2001, is
designed to provide resynchronization therapy for people
who have heart failure and problems with electrical
conduction in their hearts.
In healthy people, the four chambers of the heart
contract in synchrony to move blood through the body.
However, in many patients who have heart failure, the
electrical impulses that coordinate the contractions
of the heart’s chambers may be impaired. As a result,
in up to 50 percent of people who have advanced heart
failure, the two lower chambers, called ventricles,
no longer contract at the same time. This may worsen
the symptoms of the disease, which include shortness
of breath, fatigue, and swelling of the feet and ankles.
In cardiac resynchronization therapy, a device is
implanted in the upper chest in an attempt to resynchronize
the contractions of the ventricles by sending tiny electrical
impulses to the heart muscle. Resynchronizing the contractions
of the ventricles can help the heart pump blood throughout
the body more efficiently and reduce the symptoms.
Cardiac resynchronization therapy, also known as biventricular
pacing, is intended to complement standard drug treatment,
and dietary and lifestyle modifications.
The device, slightly larger than two stacked silver
dollars, is implanted under the skin in the chest
area, and three very thin insulated wires (leads), with
tiny electrodes on their distal ends, are maneuvered
through veins from the device to the heart: One lead
is placed to touch the inner wall of the right atrium,
another to touch the inner wall of the right ventricle
and the third lead is threaded through the coronary
sinus and placed to touch the outer wall of the left