AF Ablation
What is an AF ablation?
When to see a cardiologist
The AF ablation procedure
Recovering from an AF ablation
Complications of an AF ablation
What is an AF Ablation?
Patients with atrial fibrillation are usually offered a programme of treatments including treatment of the underlying cause (if identified), treatments to lower the risk of stroke, and treatments to control symptoms. Treatment aiming to reduce the symptoms of AF may include an AF ablation. You can read more about atrial fibrillation here.
AF ablation is a surgical technique accessing the heart from punctures at the top of one or more leg veins, to create scars and kill off small areas of heart muscle that tend to trigger atrial fibrillation. Over the past two decades many different patterns of scar creation have been trialled to treat atrial fibrillation and the consensus that has emerged is that isolation of the pulmonary veins by creating scar around them seems the most effective way to prevent AF via ablation. Different methods of creating scar exist, with two methods (radiofrequency ablation and cryoablation) in common use in the UK currently with a third (pulsed field ablation) just becoming established.
It is important to understand that, unlike ablations for other heart rhythm problems, AF ablation is unlikely to work on its own as a total cure for atrial fibrillation. A good AF ablation will reduce AF attacks dramatically, and some patients will experience years without an attack of AF after a programme of AF ablation procedures. More than one procedure may be needed to get maximum benefit, along with lifestyle changes and medications as well. There is a strong possibility that even after an initial excellent benefit from ablation, AF may return in the longer term.
When to See a Cardiologist
Symptoms such as palpitations, a racing heart beat, episodes of sudden breathlessness, and chest tightness may be suggestive of an intermittent heart rhythm problem such as atrial fibrillation.
A cardiologist - in particular a cardiac electrophysiologist (heart rhythm specialist) - has access to a range of tests that can confirm the diagnosis. Following this, they may suggest a programme of treatment to control AF and deal with the underlying causes such as being overweight or having developed obstructive sleep apnoea. It is important to note that most treatments for AF are more successful the earlier on in the disease they are used, so consulting a specialist early is vital.
Early on in the course of managing atrial fibrillation a specialist should decide whether or not it is realistic to attempt a return to normal rhythm. Some patients will experience AF only intermittently, and for them, the decision is straightforward. An AF ablation is relatively successful in patients with only intermittent AF.
If AF is continuous, however, it is likely that the disease is more established and ablation may be less successful in this setting. In this situation a specialist may recommend a “trial” of normal rhythm using a cardioversion before deciding whether AF ablation is appropriate or not.
The AF Ablation Procedure
AF ablation may be carried out under general anaesthetic or under sedation, depending on whether radiofrequency ablation, cryoablation or pulsed field ablation is used. Other minor differences, particularly in the risks of specific complications, exist between the different ablation methods. All methods currently in use in the UK have similar success rates. The absolute chance of success depends on a number of factors including how long the AF has been present, whether it is intermittent (“paroxysmal”) or continuous (“persistent”) and whether the patient has other medical conditions that impact the chance of the AF returning.
First time AF ablation using radiofrequency can take 2hrs or so. Using cryoablation or pulsed field ablation tends to be quicker.
Patients who opt for ablation under local anaesthetic will inevitably feel some parts of the ablation procedure, and the sensations depend on which method is used. For example cryoablation ablations give a feeling similar to an intense “ice cream headache” during the ablation lesions which last up to four minutes each. Radiofrequency ablation ablation is generally felt more as discomfort in the chest.
During some AF ablations there is a risk of damage to the nerve supplying the diaphragm and so this nerve is tested frequently throughout some parts of the procedure: this feels like having violent hiccoughs once per second for four minute bursts.
Access is gained to one or more veins at the top of the leg and this is used to feed wires up to the heart to conduct the AF ablation. At the end of the procedure the wires are removed, and a stitch applied at the top of the leg to prevent bleeding.
Recovering From an AF Ablation
Recovery from an AF ablation is variable. Some patients get very few after-effects, however others can get a short flu-like illness and chest pains. Some patients experience an increase in AF symptoms though this is usually temporary.
Rarely, persistent AF can start soon after an AF ablation and require a cardioversion to correct it. This is unusual, and does not necessarily predict that the AF ablation has failed. It is perfectly possible to have a lot of AF immediately after an ablation, which then resolves and remains absent for years afterwards.
The main restrictions on activity after an AF ablation relate to the puncture wounds into the femoral vein. To minimise the risk of bleeding patients are advised to avoid running, squatting, swimming and heavy lifting for two weeks after the procedure.
The DVLA also stipulate a driving ban after all EP procedures. The length of the ban depends on the licence held. For example, group 1 (car and motorbike) drivers are currently subject to a two day ban.
Complications of an AF Ablation
AF ablation does carry some significant potential complications. Around one in 100 patients will experience significant problems from the puncture wounds at the top of the leg and in extreme cases this may need surgery though the rate of this is much lower (around one in 1000). Some pain following the procedure, in the chest or around the puncture site in the leg, is common but usually mild.
Bleeding around the heart is also possible. Around one in 200 patients will need a pacemaker after an AF ablation and one in 500 will suffer a stroke. The risk of a fatal complication from an AF ablation is between one in 700 and one in 1000. The individualised risks of these complications may be higher or lower depending on the medical background of the patient and in particular patients with obesity are at higher risk of complications, and those complications being difficult to fix.