Atrial fibrillation: Rhythm control or rate control?

Rhythm control treatment has two advantages: First, it relieves the possible symptoms of atrial fibrillation. Second, it makes the heart stronger again. So rhythm control treatment is considered for the following reasons:

• Bothersome symptoms: For instance, if symptoms like a pounding heart or exhaustion can't be relieved enough through pulse-lowering treatment and measures such as drinking less alcohol and losing weight.
• An acute first episode: If you have atrial fibrillation for the first time or if you haven’t had it for long. It is thought that the chances of successfully restoring and maintaining the normal (sinus) heart rhythm will then be higher.
• Heart failure (a weak heart): If you have heart failure as well as atrial fibrillation, treatment to stabilize the rhythm of your heart can be a good idea in order to help the heart pump better. Research also suggests that catheter ablation can increase the life expectancy of some people who have atrial fibrillation and heart failure.
• If atrial fibrillation is being caused by a treatable condition: If atrial fibrillation is being caused by another medical condition, such as an overactive thyroid gland, that underlying condition is treated first. If the rhythm of the heart doesn't return to normal on its own after that, cardioversion treatment is the next step. The heart rhythm often remains stable after that.

There are sometimes other reasons for doing cardioversion – for instance, if someone is very sporty and would like their heart to be as powerful as possible.

The main potential disadvantages of resetting the normal heart rhythm are the associated risks and the limited chances of success:

• Risks of cardioversion: Cardioversion temporarily increases the risk of a stroke. If anticoagulants are used before and after cardioversion, this risk can be reduced to about 1%. But there is still a small risk.
• Risks of the stabilizing treatment: Both treatment approaches (a catheter ablation and medication to stabilize the sinus rhythm) can lead to side effects and complications, some of which are severe.
• Limited chances of success: Although it is often possible to restore the normal heart rhythm through cardioversion, the irregular rhythm can return after a while.
• Limited advantages: Research has shown that – compared to heart rate control – rhythm control treatment doesn't increase the life expectancy of most people who have atrial fibrillation. It doesn't provide better protection from complications such as strokes in most people either.

Cardioversion may not be a suitable treatment option for the following reasons too:

• The atrial fibrillation has persisted for over one year: Cardioversion is then not likely to be successful.
• Older age: Particularly in older people, it's important to carefully weigh the pros and cons of this treatment.
• Having certain other medical conditions, such as chronic kidney failure.
• Practical disadvantages: People who have cardioversion treatment often need more check-ups and have to take more medication to prevent recurrences.

A lot of people still have to take medication to control their heart rate after cardioversion too.

In atrial fibrillation, the normal heart rate is usually restored using electric shocks rather than medication. This involves placing electrodes on the upper body. These release a controlled electric signal to make the heart beat regularly. The procedure is carried out using an anesthetic lasting just a few minutes. Electrical cardioversion works in over 90 out of 100 people, and is often even successful in people who have had atrial fibrillation for quite a long time.

The normal rhythm of the heart can also be restored using a type of medication known as anti-arrhythmics (medication for heart rhythm problems, such as flecainide or propafenone). They are either injected directly into a vein or taken in the form of tablets.

After cardioversion, the normal (sinus) rhythm of the heart can be stabilized in two ways:

• Taking medication (anti-arrhythmics) over the long term.
• Catheter ablation: This procedure involves cauterizing (burning) certain areas of the heart that are often responsible for the irregular rhythm.

A thin tube ( catheter) is inserted into a vein in the groin, and pushed along the vein until it reaches the left atrium of the heart. The tip of the catheter is then heated, and the heat is used to destroy various areas of tissue on the inner wall of the heart. This treatment approach is known as radiofrequency ablation (RFA). Alternatively, extreme cold can be used to destroy the tissue by freezing it instead. This is known as cryoablation.

Anti-arrhythmics and ablation each have various pros and cons. It's best to talk to your doctor about which approach would be most suitable in your case. But it's always possible to try out medication first and then have an ablation procedure if the medication doesn't help enough or isn't well tolerated.

Because all heart-rhythm-stabilizing treatments are associated with risks and side effects, it's a good idea to find doctors who are experienced in the treatment of atrial fibrillation. Catheter ablation procedures should be carried out in centers that have enough experience.

The possible side effects of treatment with anti-arrhythmics – particularly amiodarone – are thyroid gland problems, vision problems, pneumonia, gastrointestinal (stomach and bowel) problems, and skin that is sensitive to light. These side effects usually go away if you stop taking the medication.

In very rare cases, medication to stabilize the rhythm of the heart actually causes potentially life-threatening heart rhythm problems itself. For this reason, some anti-arrhythmics shouldn't be used in people who have certain other heart problems as well.

The most common side effect of catheter ablation is bruising in the groin area, where the catheter was inserted. But it can also lead to serious complications. Damage to the heart, lungs, blood vessels or food pipe might occur during the procedure. Although these kinds of complications are rare, they can be life-threatening and may require emergency treatment.

A large study involving over 2,000 participants looked into the advantages and disadvantages of catheter ablation and treatment with medication. Data was collected over a number of years. These were the main findings:

• Both treatment approaches relieved the symptoms in most people.
• There was a noticeable improvement in 90 out of 100 people who had a catheter ablation procedure, compared to 80 out of 100 people who had treatment with medication.
• None of the treatments can guarantee that the heart rhythm will stay normal: The irregular rhythm returned within three years in about 50 out of 100 participants who had an ablation procedure, and about 70 out of 100 people who took anti-arrhythmics. About 20 out of 100 people needed more than one catheter ablation procedure.
• The medication caused side effects in 4 out of 100 people. 1 out of 100 people had a serious complication such as a life-threatening heart rhythm problem, damage to the liver, and damage to the lung.
• About 7 out of 100 people who had an ablation procedure had side effects such as bruising where the catheter was inserted or temporary chest pain. About 2 out of 100 ablation procedures led to serious complications.
• The participants needed fewer anti-arrhythmics overall in the years following their ablation procedure.
• There was no difference between the two treatments regarding life expectancy and the risk of developing related health problems such as strokes.

People who have had an ablation procedure still need to take medication (anticoagulants) to reduce the risk of blood clots. If they still have symptoms or an irregular heart rhythm despite the ablation procedure, they may have to take other medications too.

Most people can go home after 1 to 2 days. After the procedure, it's important to

• keep the area where the catheter was inserted clean and take care of the wound until it has healed,
• have showers rather than baths in the first week,
• avoid driving a car for the first two days,
• avoid strenuous activities, and sex too, for the first two days, and
• avoid lifting heavy objects for 1 to 2 weeks.

It's important to see a doctor if pain, swelling or redness develops in the groin area, or if a bump appears where the catheter was inserted.