By destroying the tissue, the electrical signals that made the heart beat irregularly should now travel through tissue that generates only a regular heartbeat.
Catheter ablation is also used to treat other irregular or harmful heart rhythms, including atrial flutter. A cardiologist specializing in the electrical activity of the heart performs the procedure.
The procedure takes place in a lab similar to an operating room but with special equipment. This includes screens and imaging technology that allow the doctor to view the heart in real time.
A catheter ablation takes place in a lab with special equipment used to display the heart in real time.
A person will receive medications through a line into a vein. Some will be asleep with a breathing tube, and others will be breathing on their own. The approach depends on the person's overall health.
The doctor will make small cuts in the groin and thread special wires (catheter wires) to the heart to sense its electrical activity and create a "map." This map directs the doctor to areas of the heart that are overactive and potentially causing A-fib.
Once the map has identified the areas for treatment, the doctor will guide the catheter wires to where ablation is needed. Next, the catheter delivers high levels of energy to scar the area. A person's heart rhythm should then return to normal.
The procedure usually takes anywhere from 2-4 hours. After it is done, the catheters and breathing tube are removed, and pressure is held on the wound sites.
The patient may have to lie flat for a few hours and limit movement of the legs to reduce the risk of bleeding from the wound sites.
Most people will be discharged the same day, but they should not attempt to drive because of the medication they have been given.
Types of ablation
An estimated 90 percent of patients with paroxysmal A-fib, which is A-fib that is not constant, have symptoms that start as a result of defects in the pulmonary vein region.
The pulmonary vein carries oxygen-rich blood to the upper left chamber of the heart before the blood is pumped out to the rest of the body. Most commonly, a doctor will scar this upper area of the heart to keep the signals that are causing A-fib from being sent out.
Sometimes, the problem areas can spread to other sections of the upper heart chambers. Then A-fib ablation is more difficult and less likely to be successful.
Another ablation type is AV node ablation with pacemaker. Pacemakers are devices that help the heart maintain a regular rhythm.
This procedure is used when a person's A-fib is not controllable with medications or ablations on other parts of their heart.
By destroying the AV node and inserting a pacemaker, the heart can return to normal rhythm without any irregular signals to disrupt the normal heartbeat.
Who is catheter ablation for?
A catheter ablation may be recommended if anti-arrhythmic medications are ineffective, or if their side effects are intolerable.
As catheter ablation is an invasive procedure, doctors don't usually recommend it as a first treatment for A-fib.
Most of the time, a person must meet certain criteria before an ablation is recommended. Examples include when:
- they have taken anti-arrhythmic medications, yet their A-fib continues
- they can't tolerate the side effects of anti-arrhythmic medication
- their condition is declining, and they have symptoms of heart failure, or a reduction in how much blood the heart pumps out
Athletes sometimes experience A-fib due to the extra demands on their hearts. When this is the case, a doctor may recommend an ablation as a first treatment.
A doctor will not recommend ablation because a patient no longer wishes to take anticoagulants to reduce their risk of blood clots. As an ablation is an invasive procedure, the risks can sometimes outweigh the benefits. This is why the case is made for taking anticoagulants instead of having an ablation procedure most of the time.
Benefits and risks
A-fib increases risk of stroke or other blood clot-related conditions. It can also affect a person's quality of life and overall activity levels. A-fib will worsen if left untreated, and can lead to heart failure. Treating it as early as possible can slow or possibly stop it getting worse.
By correcting the underlying cause with A-fib ablation, a person can live life without worrying about the heart palpitations or shortness of breath that occur.
With any procedure, however, there are some risks. The most significant is that a doctor might damage a blood vessel while inserting, removing, or moving the catheters. Other organs or structures that are close by, such as the food pipe may also be affected.
Infection at the entry site is another possibility or a person may have an adverse reaction to the medications that puts them to sleep. Even so, A-fib ablation is a "low-risk" procedure, according to the American Heart Association.
How to prepare for a catheter ablation
Before a catheter ablation, a doctor may conduct many types of cardiac testing to measure overall heart health. These tests can help work out the likelihood of an ablation being successful, and can show the doctor where to perform the procedure.
Several tests may be done before the procedure, including Holter monitor testing and blood testing.
Examples of these tests include:
- Blood testing, to determine if a person's blood is at a therapeutic level.
- Computed tomography (CT), where a scan shows a doctor the heart and its structures and identifies abnormalities.
- Electrocardiogram, which measures the heart's electrical activity and rhythm.
- Holter monitor testing, where a person wears a monitor that detects and records the heart's rhythms.
- Transthoracic echocardiogram, involving a non-invasive test that estimates the functioning of the heart valves and the amount of blood being pumped to the body.
- Transesophageal echocardiogram, which involves putting a probe down the throat to more closely view the chambers of the heart.
Doctors will give patients a list of things to do the day before the procedure, such as not eating or drinking after midnight. They may ask them to use a special soap that helps kill germs and reduces the risk of infection.
A doctor will also tell a person what medications they should take, or in some cases not take, before the ablation.
Recovery and outlook
After an A-fib ablation, many people return home the same day. A doctor will usually advise against heavy lifting and strenuous exercise for about 3 days. Patients can usually resume their regular activities, such as going back to work, the day after an A-fib ablation.
A patient should seek emergency medical attention if they experience the following symptoms:
- swelling at the entry site that is quickly enlarging
- pain in the chest that radiates to the arm, neck, or jaw
- a foot turns numb, cold, or blue-tinged
- the heart begins to beat very fast or irregularly
- breathing is difficult and a person becomes short of breath
A-fib ablations are not always successful. In one study, the success rate was 73.6 percent and some people remained on anti-arrhythmic or other drugs to prevent A-fib from returning.
Furthermore, an A-fib ablation may only work for a short time. A repeat procedure may be carried out to allow the doctor to find any remaining areas that are transmitting faulty electric signals.
If A-fib ablation is unsuccessful, there are other invasive procedures available. However, these often carry added risks. As A-fib ablation techniques improve, the procedure is likely to be more effective in helping people return their heart rhythms to normal.