Atrial Fibrillation Ablation
What is Catheter Ablation?
Catheter ablation is a minimally invasive technique used to treat a variety of heart rhythm disorders. It is performed in a special operating theatre called a cardiac catheterization laboratory, or cath lab for short. A catheter is a fine wire that can be threaded through a blood vessel via a needlehole in the skin and placed in the heart. Usually, a blood vessel at the top of the right thigh in the groin area is used for access to the heart.
Up to 4 catheters may be used during the procedure. Each catheter has electrodes on its end that can monitor the heart’s internal electrical activity, akin to performing an internal ECG of the heart. An ablation catheter can be used to deliver radiofrequency energy to the problem area in the heart. Radiofrequency energy is a low power, high frequency energy that is delivered to a tiny region of heart tissue near the tip of the catheter, thus cauterizing or ablating the tissue.
Radiofrequency energy has been used for decades by surgeons to cut tissue and to stop bleeding. For the treatment of heart rhythm disorders, radio-frequency energy at a much lower power is used to ablate tissue within the heart that is responsible for initiating or perpetuating your arrhythmia.
AF ablation is designed to cure your symptoms, improve your quality of life, and prevent disease progression. It is recommended for repeated or prolonged episodes of AF, especially if symptoms of medication side effects have been intrusive. AF ablation is also recommended to prevent deterioration of the heart function, even in the absence of symptoms. There is now good evidence that earlier intervention produces better results.
This is normally an elective procedure. You will receive a letter from the hospital bookings clerk or doctor’s secretary outlining the date, time, and other details of your hospital admission. A nurse may call you to confirm your personal and medical details.
You may require a blood test and heart scan prior to your procedure. You will receive specific instructions about any medication changes that are necessary prior to your procedure. If you are unsure about the instructions, please do contact the clinic for clarification.
You must fast for at least six hours before your ablation. If your procedure is in the morning or early afternoon, do not eat or drink after midnight, except for a sip of water to help you swallow your pills.If your procedure is in the mid to late afternoon, you may have a light, early breakfast.
You will be admitted to a hospital bed on the day of your procedure.You will be provided a hospital gown. Pre-operative checks will be performed and your groin area will be shaved before transfer to the cath lab. The cath lab has a movable patient bed, an X-ray machine, ECG monitors, and other equipment.
ECG electrodes and patches will be attached to your chest and back. These will feel cool on your skin. An anaesthetist will insert a fine intravenous tube usually into the back of your hand before administering the general anaesthetic medication. A second tube will be placed into the artery of your wrist to monitor blood pressure.
The entire AF ablation procedure will then be performed while you are asleep under general anaesthesia. This may take an hour or so depending on the complexity of your procedure.
While you are under anesthesia, an ultrasound scanner is passed down your throat to confirm no clots in the heart.
Normally 2 needle holes are placed in vein at the top of the right thigh in the groin area through which catheters are passed and positioned in the heart.
The catheters are positioned using X-ray, ultrasound, and a computerized 3D mapping system to guide placement. They first enter the right atrium. Because AF begins in the left atrium, a needle is required to cross from the right to the left side through the thin membrane that divides the 2 upper chambers. The defect in the membrane seals off on its own.
In AF, abnormal electrical activity can originate from any of the pulmonary veins. The tissue around these veins is ablated to prevent any electrical impulses from leaving the veins and triggering AF. If you have persistent AF, additional ablation may be required to address other areas responsible for perpetuating AF. Following ablation, further testing is performed to conclude the procedure.
AF ablation has been developed over 2 decades and is now a routine procedure in many hospitals around the world. The adverse event rate has fallen dramatically with improvements in techniques and technology. There is an overall 1% risk of a serious adverse event occurring, which your doctor will discuss with you in clinic. If there is a chance you are pregnant, please do notify the doctor performing the procedure.
You will wake up in the recovery ward before being transferred to a normal hospital ward. Bed rest is required for at least 3 hours after the procedure. During this time, it is important to keep your legs straight and your head relaxed on the pillow.
It is usual to stay in hospital for 1 night after the procedure. Your heart rhythm will be monitored during this time. You will be prescribed the following medications:
- Blood thinner.You will require an 8 week course to prevent blood clots in the heart. Depending on your situation, you may need to continue your blood thinner for longer.
- Antiarrhythmic medications. Your usual antiarrhythmic medications may be continued for 8 weeks before these are reduced and subsequently stopped.
After the procedure, it is common to have a sore throat and some mild chest discomfort. You may also have some discomfort and bruising in the groin. Symptoms will typically improve over several days. You should avoid exercise, driving, and heavy lifting for at least 5 days after the procedure. Please arrange to take 1 week off work and driving for your recovery.
You may experience a migraine accompanied by flashing lights or blind spots. While you might be alarmed, you are not having a stroke. Migraines are common after the procedure and generally pass after a week or so.
Some individuals experience bloating and indigestion due to irritation of the gullet or a nerve near the heart called the vagus nerve. This normally settles after a week or so.
Because it takes several weeks for the areas of ablation to heal and form scars, it is not uncommon to experience abnormal or irregular heartbeat or rhythm for up to 8 weeks after the procedure. Rarely, palpitations may be worse for a few weeks after the procedure due to inflammation where the ablation was performed. This is the reason why antiarrhythmic medications are typically continued for 8 weeks post-ablation.
You may notice that your resting heart rate increases following AF ablation to 80-90 beats per minute. This occasional side effect has no ill effects and may take 6 to 12 months to normalize.
You will be issued further discharge information and instructions which can be found here. It is important that you read and retain these instructions with you for 8 weeks following discharge. You will need to arrange for a family member or friend to pick you up from the hospital once you are discharged. A follow-up appointment will be arranged 8 weeks post-procedure or earlier if necessary.
Information for Patients
- Wound care.The puncture site at the top of the right thigh in the groin area will take approximately 1 week to heal. Observe the area every day and keep it dry and clean. Avoiding applying soap and talcum powder to the site. A pea-sized lump and a minimal amount of bruising is normal and may last for up to 2 weeks.If there is increasing pain, active bleeding, or an expanding mass in the groin, please make immediate contact with the clinic, or proceed immediately to your local emergency service for assessment, bringing this information sheet with you.
- Rest and recovery. To best facilitate healing of the puncture site, take at least 1 week off work. Avoid exercise, driving, abdominal straining, and heavy lifting during this period. Rest and gentle walking at home is permitted. After 1 week you may return to your usual activities without restriction, unless advised otherwise.
- Palpitations. You may develop recurrent palpitations during the 8 week healing period. If these come and go on their own, they are best managed with medications. If they are continuous over >24 h, please contact the clinic as it may be necessary to arrange a small electric shock to restore normal rhythm.
- Red flag symptoms. Mild chest pain that is worse with lying down or breathing in is normal following your procedure and will resolve over 1-2 weeks. However, if you develop a fever with temperature >38C, weakness or numbness of a limb, difficulty speaking, difficult or painful swallowing, vomiting, or passing blood, please make immediate contact with the clinic, or proceed immediately to your local emergency service, bringing this information sheet with you.
- Contact details. Prior to your first follow-up appointment, it is best to contact the treating team for any post-procedure issues rather than your GP or general cardiologist who may not be so familiar with details of the procedure. For public patients, contact the Alfred Heart Centre on 03 9076 3263. For private patients, contact the Heart Rhythm Clinic on 03 8560 0535. If the clinic is closed or the treating doctor or nurse not available, please proceed to your GP or local emergency service for evaluation.
Information for Doctors
This patient has undergone radiofrequency catheter ablation for atrial fibrillation, and may present with one of the following issues. Should you have any concerns, please do not hesitate to contact Dr Han Ling through the Heart Rhythm Clinic on 03 8560 0535 or through the Alfred Hospital Switchboard on 03 9076 2000.
- Vascular access issues. The ablation procedure typically involves 4 sheathes placed in the right femoral vein with continuous perioperative anticoagulation. Femoral arterial access is not required. Ongoing issues with bleeding are therefore normally easily addressed with manual compression. However, if there has been increasing pain or and expanding mass, please consider ultrasonography to exclude AV fistula or false femoral aneurysm in the unlikely event of unrecognized arterial injury.
- Recurrent atrial arrhythmia. If the patient presents with AF or atrial flutter in the first 2-3 months post ablation, electrical cardioversion would be beneficial if this could be accommodated in the emergency department setting. Documentation of the arrhythmia is essential for future planning. Kindly provide a hard copy of the discharge summary and relevant ECG traces to the patient and to fax: 03 8080 6460.
- Atrioeosophageal fistula. This rare (<1:2000) but serious complication develops slowly, usually presenting up to 6 weeks post procedure. Presentation typically involves fever (T>38 C) in combination with stroke, chest pain, difficult or painful swallowing, vomiting, or passing blood. Oesophageal instrumentation is contraindicated (eg upper GI endoscopy, transoesophageal echocardiography). The test of choice for diagnosing the problem is a CT chest with IV contrast done in an experienced centre.
The success rate varies from case to case according to a number of factors. Overall, your total AF burden is expected to reduce by >95%, and be completely eliminated in the majority of cases. The longer the heart has spent in AF, the more challenging it is to restore normal rhythm. In some cases, repeat procedures may be considered if AF returns. Your doctor will discuss your specific circumstances and expected results with you.