Magnetically guided catheter aids radio frequency ablation treatment of
heart
21 April 2006
A remotely-controlled catheter device guided by magnetic fields provides
a safe and practical method for delivering radio frequency ablation
treatment in the hearts of patients with atrial fibrillation, according to a
new study in the April 4, 2006, issue of the Journal of the American College
of Cardiology.
“Based on our experience with remote navigation and ablation technology,
a new era in interventional electrophysiology is beginning as magnetic, very
soft catheters can be navigated in the heart more precisely and safely than
manual catheters without risk of major complications, even in less
experienced centers,” said Carlo Pappone, M.D., Ph.D. from the Department of
Electrophysiology, San Raffaele University Hospital in Milan, Italy.
Atrial fibrillation is an abnormal heart rhythm in which the upper
chambers of the heart flutter, and do not pump blood normally. If the
condition cannot be managed with medications, some patients are treated with
radio frequency ablation. The technique uses a high energy pulse to destroy
a small area of heart muscle cells, in order to prevent them from conducting
nerve signals that trigger fibrillation.
Typically the radio frequency pulse is emitted by from the tip of a
catheter threaded through blood vessels into the heart until it is
positioned next to the target area. Conventional catheters are somewhat
stiff, so they can be pushed and pulled through blood vessels, and their
tips can be curled and pointed by an operator standing by the patient. The
device tested in this trial uses a very soft, limp tip that has a magnet on
the end. Rather than manually pointing the catheter tip, the operator of
this device uses a computer to control a magnetic field that robotically
moves the catheter tip. The principle is the same as a compass needle
pointing to magnetic north; allowing this device to steer the magnetic
catheter in three dimensions to a target visualized on 3-D scans of the
patient's heart.
“Catheter ablation for atrial fibrillation is now an important treatment
for this common disorder, but the current strategy of manual catheter
manipulation is highly operator-dependent, with a long and variable learning
curve and a great potential for both inefficacy and complications in
inexperienced hands. Robotic navigation may increase the ability of
inexperienced operators to perform this procedure easily and safely, as it
is most dependent on a well-trained team rather than on a single operator,”
Dr. Pappone said.
Since catheter procedures of this type require frequent use of X-rays to
track the location of the target and the catheter tip, another advantage of
remote navigation is that the operator can work from a shielded control
room, rather than having to stand next to the patient for several hours
while wearing protective lead aprons.
This first trial of the robotic magnetic navigation system in patients
with atrial fibrillation involved 40 participants whose conditions were not
adequately controlled by medication. After encountering some difficulties in
the first three patients, the researchers said the remaining procedures went
smoothly. In all, the catheter tip was successfully guided by magnetic
navigation to the target and radio frequency ablation was applied in 38 of
the 40 study participants. There were no reported complications during the
procedures.
“Based on our results, we believe that incorporation of remote navigation
and ablation in the electrophysiology laboratory may represent a true
revolution regardless of age and experience of the operators leading to a
seismic change in electrophysiologic paradigms for many laboratories
worldwide. People always have had a love/hate relationship with robots, but
this psychological barrier must be overcome. After performing more than
10,000 procedures with manually deflectable catheters, I have become
enthusiastic for this emerging field,” Dr. Pappone said.
Further information : The
full study is available on the ACC website
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