Heart Atrial Fibrillation:

Mayo Clinic researchers are advancing
a less invasive procedure to treat atrial

For patients, catheter ablation offers
less risk and faster recovery than
open-heart surgery. For cardiologists,
the challenge lies in knowing where to
ablate when they can't directly see the
heart. Mayo's latest innovation helps
its cardiologists do just that by
"immersing" them in a five-dimensional
view of the heart.
Like 3D procedures, the new
technology uses catheters to insert
tiny electrodes into the heart, which
send images of the heart's 3-D
anatomic structure to a computer

The 5D system, however, uses a
unique computational platform to "take
the physician inside the heart in 5-D,
visualizing the heart walls, the
electrical activity within those walls and
the catheter as the physician
navigates to the treatment site," says
Richard Robb, Ph.D., director of Mayo
Biomedical Imaging Resources. "The
ablation can actually be observed as it
is administered."

Dr. Robb estimates that the new
system potentially increases the
effectiveness of catheter ablation to 95
percent – as effective as open-heart

Dr. Robb and Douglas Packer, M.D.,
director of Mayo's Heart Rhythm
Service, are leaders of Catheter
ABlation vs. ANti-arrhythmic drug
therapy for Atrial Fibrillation or
CABANA, a clinical study to evaluate
catheter ablation.

CABANA (Catheter Ablation Versus
Anti-arrhythmic Drug Therapy for Atrial
Fibrillation), the study involves 3,000
patients and 140 centers worldwide.
Led by Mayo, CABANA aims to
discover if ablation is more effective
than medication for treating atrial

CABANA is the first large-scale study
of the procedure. CABANA's six-year
span allows researchers to examine
the procedure's impact on mortality,
hospital costs and a patient's quality-of-
life. Eventually, catheter ablation may
be a first-line treatment for atrial
fibrillation rather than an option for
patients who don't improve after drug

In October 2010 German drugmaker
Boehringer Ingelheim won the first U.S.
approval for a new stroke-fighting
medicine that will compete in an
estimated $10 billion market for drugs
to replace the 65-year-old blood
thinner warfarin.
Boehringer's drug, Pradaxa, is cleared
for preventing strokes in patients with
a type of irregular heart beat.
The approval gives Boehringer a head
start over several other drugmakers,
including partners Bayer and Johnson
& Johnson, and Bristol-Myers Squibb
Co and Pfizer, that are working on
competing drugs.

Pradaxa and potential rivals are
alternatives to warfarin, a problematic
medicine originally developed as rat

Pradaxa is an anticoagulant that acts
by inhibiting thrombin, an enzyme in
the blood that is involved in blood
clotting. The FDA said the safety and
effectiveness of Pradaxa were studied
in a clinical trial comparing Pradaxa
with the anticoagulant warfarin. In the
trial, patients taking Pradaxa had fewer
strokes than those who took warfarin.

Others in the race:
Bayer AG  has teamed up with
Johnson & Johnson  to gain FDA
approval of rivaroxaban in the U.S. In
2009, an FDA advisory panel
recommended rivaroxaban be
approved for short-term use in patients
undergoing knee or hip replacements.
The FDA so far hasn't approved the
drug and asked Bayer for more
Rivaroxaban is approved in Europe for
use in certain surgery patients and is
sold under the brand name Xarelto.
The drug is also being studied in atrial
fibrillation patients.

Bristol-Myers Squibb Co.  and Pfizer
Inc.  are co-developing apixaban, and
Merck & Co. is developing a product
known as betrixaban with closely held
Portola Inc. Also, Daiichi Sankyo Co.  
is developing a drug called edoxaban.

Cameron Health's S-ICD System:
delivers a jolt through a sensor
implanted under a patient's skin, but
not wired to a patient's heart.
The system delivers a bigger kick-start
to the heart than conventional devices.
It is also less likely to trigger false
alarms - where the patient is given an
unnecessary shock.
And because the leads from the device
don't go directly into the heart, there is
a reduced risk of infection, say

Findings from three clinical trials show
the new device, the Subcutaneous
Implantable Defibrillator (S-ICD),
detected and treated successfully all
episodes of severe rhythm disturbance
over ten months.
Implantable defibrillators provide round-
the-clock protection for hundreds of
thousands of patients with heart
problems, with at least 30,000
implanted in Britain, though many more
go untreated.
Around 70,000 Britons die every year
from sudden cardiac death caused by
arrhythmia, a disturbance or
irregularity of the heartbeat.
Conventional implanted defibrillators
require at least one lead placed
directly to the heart - usually threaded
through a vein.

This senses dangerous changes in
heart rhythm and delivers a lifesaving
But the leads on these devices are
'highly likely' to cause infections in
patients who then need treatment or
even further surgery to remove them,
says Dr Grace.
'This deters some patients from having
them implanted, and may mean
doctors are less willing to recommend
them,' he says.

The new battery-operated system has
one wire going across the chest under
the skin - this wire is connected to the
device implanted beneath the skin,
which delivers the shock.
The added distance from the heart
means a more powerful shock can be
delivered than from conventional
devices - about 2.5 times stronger.
Made by Cameron Health in the U.S.,
the device costs about £13,000 -
similar to existing devices - and lasts
five years before it needs to be

Catheter Robotics of New Jersey has
developed a fully automatic robotic
arm to be used in catheter ablation.
While the catheters which performed
the ablation in the Sensei system are
controlled by hand, from either inside
the theatre or using a network controls
on the outside.
The difference with the new robot is
that the wires go straight into the
patient's body.
They are then controlled with two
buttons - one for the direction of the
catheter and one for it to go in and out.


catheter ablation equipment by C R