Treatment Overview
If medication is not effective or not
tolerated for
atrial fibrillation, a nonsurgical procedure called
catheter ablation may be chosen. Catheter ablation for atrial fibrillation is
relatively new and is still being studied.
In this procedure
thin, flexible wires are inserted into a vein in the groin and threaded up
through the vein and into the heart. There is an electrode at the tip of the
wires. The electrode sends out radio waves that create heat. This heat destroys
the heart tissue that causes atrial fibrillation or the heart tissue that keeps
it happening.
Ablation procedures either try to cure atrial
fibrillation (focal ablation, circumferential ablation, and pulmonary vein
ablation) or try to control your symptoms (nodal ablation).
Ablation to cure atrial fibrillation
Focal and
circumferential catheter ablation are used to try to cure atrial fibrillation.
Focal ablation, also known as targeted ablation, is used to destroy the
specific areas in the heart that are firing off abnormal electrical impulses
and causing atrial fibrillation. Circumferential ablation is used to destroy
the tissue that lets atrial fibrillation continue. Sometimes, a doctor uses
both focal and circumferential ablation.
Pulmonary vein ablation
is also used to try to cure atrial fibrillation. Sometimes, abnormal impulses
come from inside a pulmonary vein and cause atrial fibrillation. (The pulmonary
veins bring blood back from the lungs to the heart.) Catheter ablation in a
pulmonary vein can block these impulses and keep atrial fibrillation from
happening.
A pacemaker is usually not needed when catheter
ablation is done on the pulmonary vein or other targeted tissue.
View a
slideshow
of pulmonary vein or focal ablation
to see how the heart's electrical
system works, how atrial fibrillation happens, and how pulmonary vein or focal
ablation is performed.
In some cases, catheter ablation may be
done by applying radiofrequency energy to the outside or inside surface of the
heart during open-heart surgery. This may be an option if you are already
having heart surgery for another reason, such as
coronary artery bypass or valve replacement
surgery.
Ablation to control symptoms of atrial fibrillation
Nodal catheter ablation, also known as AV node ablation, can control
symptoms of atrial fibrillation when the cause cannot be stopped. You may need
AV node ablation if targeted or pulmonary vein ablation did not stop your
atrial fibrillation, or if these procedures will not help you. With AV node
ablation, the entire
atrioventricular (AV) node is destroyed. After the AV
node is destroyed, it can no longer send impulses to the lower chambers of the
heart (ventricles). This controls atrial fibrillation symptoms.
After AV node ablation, a permanent
pacemaker is needed to regulate your heart rhythm.
Nodal ablation can control your heart rate and reduce your symptoms, but it
does not prevent or cure atrial fibrillation. So you will probably need to take
anticoagulation therapy such as warfarin.
View a
slideshow
of AV node ablation
to see how the heart's electrical system works, how
atrial fibrillation happens, and how AV node ablation is performed.
You will be given medication to help you relax. A
local anesthetic will numb the site where the catheter
is inserted. The procedure is done in a hospital where you can be monitored
carefully.
What To Expect After Treatment
Recovery from catheter ablation is
usually quick. You may be hospitalized for 1 to 2 days so that your doctor can
monitor your heart rate. After the procedure, you will need to take
anticoagulation medication, such as warfarin (Coumadin, for example) for at
least 3 months.
You might feel a flutter in your heart after the
ablation procedure. The flutter usually goes away after your heart heals. If
your flutter does not go away, you may need a second ablation procedure.
Why It Is Done
Focal ablation or pulmonary vein
ablation that targets tissues that generate irregular electrical impulses is
often used for
paroxysmal atrial fibrillation in people who have
severe symptoms and who have not been helped by medicines.
AV
node, or nodal, catheter ablation is occasionally used when persistent chronic
atrial fibrillation does not respond to treatment with medicines and symptoms
continue to be bothersome. It is most often used in people who have
difficult-to-control heart rates.
How Well It Works
Catheter ablation to cure atrial
fibrillation (focal or pulmonary vein ablation, for example) is more successful
in people with paroxysmal atrial fibrillation than in those with persistent
atrial fibrillation.
In a pulmonary vein ablation study, 74% of
patients who had long-term atrial fibrillation with symptoms were free of
atrial fibrillation for at least one year after undergoing 1 or 2 ablation
procedures.1
AV node ablation followed by
pacemaker implantation reduces cardiac symptoms and improves exercise
tolerance, quality of life, and the amount of blood pumped with each heartbeat
(ejection fraction).2
Risks
Catheter ablation to cure atrial fibrillation
is an invasive procedure and has some serious risks. These risks include:
- Stroke. A stroke is a sudden disruption
in blood flow to a portion of the brain. The disruption in blood flow is caused
by a blockage or by bleeding of a blood vessel.
- Heart attack.
- Puncture of the
heart.
- Need for emergency heart surgery.
- Damage to the
pulmonary vein.
- Pulmonary vein stenosis, which is a narrowing of
the pulmonary vein.
- Phrenic nerve injury, which can cause paralysis
of the
diaphragm. The diaphragm is a large muscle that
separates the chest cavity (containing the lungs and heart) from the abdominal
cavity. It helps draw air in and out of the lungs.
- Pericarditis. Pericarditis is inflammation of the sac
(pericardium) that surrounds and protects the heart.
- Cardiac tamponade. This is an emergency condition that
can lead to death. It may require emergency heart
surgery.
- Atrio-esophageal fistula. In this life-threatening
condition, a hole forms between the heart's upper chamber and the esophagus.
- Bleeding from the puncture site where the wires are
inserted.
- New abnormal heart rhythms (arrhythmias).
- Sudden death.
The risks of catheter ablation of the AV node
include:
- Bruising.
- A leaking blood
vessel.
- Stroke.
- Puncture of the
heart.
- Arrhythmias.
- Sudden death.2
What To Think About
A
pacemaker will be implanted to maintain normal heart
rhythm after AV node ablation.
After AV node ablation, you will
need to take anticoagulant medications because you will still be at risk for
stroke.
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