Catheter Ablation for Atrial Fibrillation
Catheter ablation is a procedure which uses special wires that are advanced into the heart to give treatment to abnormal electrical impulses that cause heart rhythm problems (arrhythmias). In people who experience atrial fibrillation, the treatment is directed around the pulmonary veins (blood vessels bringing blood back from the lungs to the heart) where they connect to the left atrium (left top chamber of the heart). Research has shown that most abnormal electrical impulses that trigger episodes of atrial fibrillation come from this region of the heart.
Why Perform Ablation for Atrial Fibrillation?
Some patients continue to experience severe symptoms from their atrial fibrillation despite having tried several medications and other treatments such as cardioversions (electrical shock under anaesthetic to reset the heart rhythm). Catheter ablation is a new treatment which is effective at controlling or even curing atrial fibrillation in such people.
How Successful is the Procedure?
The success rates of this type of treatment for restoring and maintaining normal heart rhythm for at least 1 year are greater than 70% in people who are having intermittent episodes of atrial fibrillation. The success rates are lower if the heart has been in atrial fibrillation persistently for some time. You should understand that several techniques for catheter ablation for atrial fibrillation have been developed around the world, and that success rates can vary.
Small numbers of patients can get their atrial fibrillation back over time, in which case medications can be retried or a repeat procedure can be performed to improve the success.
What does the Procedure Involve?
The procedure is performed under a general anaesthetic. While you are asleep, small incisions are made in both groins and several catheters are passed up through the veins into the heart. Two small punctures are made from inside the heart to advance the catheters across into the left atrium where the treatment will be delivered.
First, information is collected with the catheters from the inside of the heart. Then ablation treatment is performed around each of the connections of the pulmonary veins with the left atrium. Information is then recollected to ensure that electrical impulses are no longer able to exit from inside of the pulmonary veins to trigger atrial fibrillation (so called "pulmonary vein isolation"). Other areas of the heart will be checked for abnormal electrical impulses which could cause atrial fibrillation, and additional treatment may be performed.
At the completion of the procedure pressure will be applied to seal over the incisions. You will be taken to recovery and then back to your ward bed for monitoring overnight. You will be asked to lie still for 6 hours to prevent any bleeding from the groins.
An important safety aspect of the procedure is preventing blood clot from forming on the catheters during the procedure, or inside the heart during the healing period, which could potentially travel off in the bloodstream and cause a stroke. You will be required to take Warfarin treatment for at least 4 weeks before, and to have a satisfactory blood level (INR test) on the day of the procedure. The procedure can be safely performed whilst taking Warfarin therapy, and your Cardiologist will use additional blood thinners during the ablation treatment.
What should I Expect?
Do not eat or drink anything for 6 hours prior to your catheter ablation procedure. You will be instructed to stop any antiarrhythmic (heart rhythm) medications 3 days prior. A CT scan of your heart will be performed immediately before your procedure. In the first 24 hours after your procedure it is common to have some minor bruising and discomfort at the incision sites in the groin and some mild chest discomfort. You will generally be discharged from hospital the morning after your procedure.
What Happens after Discharge?
You will be instructed to continue your Warfarin treatment for at least 3 months, and possibly longer. It is common to have some palpitations and even episodes of atrial fibrillation in the first 2 to 3 months of healing, and you will be advised to continue any antiarrhythmic medications for this period. You should avoid exercise and heavy lifting for the first few days, and then resume normal activities after the first week.