What happens during catheter ablation?

In ablation, a flexible tube called a catheter is used to destroy (ablate) a specific part of the heart tissue, typically using electricity or extreme cold. This procedure is also called cardiac ablation. A small scar forms where the tissue is destroyed. The procedure is especially effective for treating heart rhythm disorders (arrhythmias).

It is considered to be minimally invasive because doctors only need to make a small incision (cut) in the groin.

How can this procedure prevent heart rhythm disorders?

Heart rhythm disorders often develop when certain parts of the heart are already damaged – for instance, by something like coronary artery disease. This damage leads to abnormal electrical signals, and the heart gets out of sync. By destroying the tissue in that area, doctors can stop the abnormal signals from being sent, or at least prevent them from spreading to the rest of the heart.

Illustration: A catheter is used to destroy the areas that are causing heart rhythm disorders

Some heart rhythm disorders are caused by congenital ("at birth") abnormalities that result in extra electrical pathways in the heart. If electrical signals travel along these pathways, they may disrupt the heart’s normal rhythm and cause problems – like making the lower heart chambers (ventricles) beat too quickly. Catheter ablation can prevent that from happening by "blocking" the additional pathways.

What needs to be done before surgery?

A number of things need to be done before the abnormal heart tissue can be destroyed using a . Doctors will first find out exactly what the heart condition is. They will also see whether there is an increased risk of complications, perhaps due to other serious health problems.

For this reason, a number of examinations are carried out before the procedure – mainly an ECG and an ultrasound scan of the heart (echocardiography). There's also another important examination, known as an electrophysiology (EP) study. But it's usually done as part of the procedure for the ablation, right before the abnormal heart tissue is destroyed.

You can discuss any questions you still have during the pre-surgery consultation, before signing the consent form needed to have the procedure done.

What does catheter ablation involve?

The procedure is done in a catheterization laboratory (cath lab). This is usually in a hospital, but it may also be in a specialist cardiology practice, where the ablation is done as an outpatient procedure. First, the skin around the groin is disinfected and numbed with an anesthetic. Then the doctor makes a cut there and inserts the into a blood vessel. The is gently pushed along the blood vessel, to the heart. This does not hurt. A general anesthetic isn’t usually needed. But you can ask for a sedative if you like.

The heart rhythm is monitored with an ECG during the procedure. The chest is usually scanned with an x-ray to see the position of the on a screen. This is often not necessary, though. Instead, the position of the is then monitored by a computer that creates a three-dimensional (3D) image based on previous heart scans.

Electrophysiology study

As soon as the tip of the has reached the area that is thought to be causing the heart rhythm disorder, the doctor does an electrophysiology study: They send bursts of electricity from the to see how the heart tissue reacts. That way, they can work out exactly which parts of the heart need to be destroyed.

Ablation with electricity or extreme cold

The tissue is typically destroyed (ablated) right after that. This normally involves using electricity to heat the exact area where the scars should form. The technical term for this procedure is radiofrequency ablation. Other techniques are sometimes used instead. For instance, the tissue can be destroyed using extreme cold (cryoablation).

What happens after the procedure?

The cut in the groin area is usually sewn up with one and covered with a dressing. A special compression bandage may be used if needed.

You will then stay in the hospital for 12 to 48 hours for observation. The amount of time will depend on your overall health and the type of heart problem. Your heart rhythm will be monitored regularly during that time. Before returning home, you will usually have other examinations (such as another echocardiography) and the in your groin will be removed.

After the procedure, it's important to

  • keep the cut in the groin 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 for the first two days, and
  • not lift any heavy objects and not ride a bike for the first one to two weeks.

It is important to see a doctor if the groin area hurts, swells or reddens after the procedure, or if a bump appears where the was inserted.

What are the risks of catheter ablation?

The electrical signals used for the electrophysiology study and for the ablation itself can cause heart rhythm disorders. But doctors can usually return the heart rhythm to normal straight away using the inserted instruments. Catheter ablation can also lead to a permanent heart rhythm disorder such as AV block. Other possible complications include:

  • Bruising around the area where the was inserted
  • Bleeding after surgery
  • Damage to the heart, blood vessels or nerves
  • A build-up of fluid around the heart (pericardial effusion)

Brugada J, Katritsis DG, Arbelo E et al. 2019 ESC Guidelines for the management of patients with supraventricular tachycardia: The Task Force for the management of patients with supraventricular tachycardia of the European Society of Cardiology (ESC). Eur Heart J 2020; 41(5): 655-720.

Hindricks G, Eckardt L, Gramlich M et al. Kommentar zu den Leitlinien (2020) der ESC zur Diagnose und Behandlung von Vorhofflimmern. Kardiologe 2021; 15: 354-363.

Hindricks G, Potpara T, Dagres N et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS): The Task Force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. Eur Heart J 2021; 42(5): 373-498.

Kasper DL, Fauci AS, Hauser SL et al. Harrison's Principles of Internal Medicine. New York: McGraw-Hill; 2015.

Kuck KH, Böcker D, Chun J et al. Qualitätskriterien zur Durchführung der Katheterablation von Vorhofflimmern. Positionspapier der Deutschen Gesellschaft für Kardiologie. Kardiologe 2017; 11: 161-182.

Page RL, Joglar JA, Caldwell MA et al. 2015 ACC/AHA/HRS Guideline for the Management of Adult Patients With Supraventricular Tachycardia: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol 2016; 67(13): 1575-1623.

Pschyrembel Online. 2023.

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Updated on June 6, 2023

Next planned update: 2026


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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