Radiofrequency ablation (RFA): when it is needed, how it is done, risks

According to MedlinePlus, ablation creates a scar in the small area of heart tissue that is causing the rhythm problem. The radiofrequency method uses heat, while cryoablation uses cold. Which one is chosen depends on the type of rhythm. The procedure is done with a catheter, that is, a thin, flexible instrument passed through a blood vessel to the heart.

MedlinePlus lists the following conditions:

• AVNRT: a tachycardia in which the signal circles inside the electrical node between the atria and the ventricles;
• accessory electrical pathways, including WPW syndrome (the heart has an extra signal pathway);
• atrial fibrillation;
• atrial flutter;
• ventricular tachycardia: a fast rhythm that starts in the lower chambers of the heart.

The publicly available summaries of the ESC guidelines describe three situations:

• Supraventricular tachycardia. According to the ACC summary of the 2019 ESC guideline, in re-entry arrhythmias (the signal circles around a loop) and most focal arrhythmias (the signal starts from one point), ablation should be offered as a first choice after a detailed discussion of the risks and benefits.
• Atrial fibrillation. According to a review of the 2024 ESC/EACTS guideline, in the type that comes and goes (paroxysmal), catheter ablation is one of the first-choice options for suitable people, but it is not done in every patient.
• Ventricular arrhythmias. According to the ACC summary of the 2022 ESC guideline, it is a first choice in idiopathic (no cause found) ventricular tachycardia that causes symptoms, and in symptomatic extrasystoles (extra beats) that start from certain areas of the ventricles.

This does not mean it is mandatory. You make the decision together with your doctor.

MedlinePlus advises telling your doctor about all your medicines, including blood thinners, and letting them know if you have a cold or a fever. Usually you cannot eat or drink after midnight. The procedure goes like this:

1. A sedative is given, and the skin in the neck, arm or groin area is numbed.
2. A catheter is passed through a blood vessel to the heart, and the doctor follows it on a live X-ray image.
3. Electrodes (the parts that sense the signal) locate the problem area.
4. Energy is delivered and a small scar is created.

You may feel brief burning when a medicine is injected, your heart beating faster or harder, mild lightheadedness, and burning when the energy is delivered.

Sources differ on how long it takes: MedlinePlus says 4 hours or more. For atrial fibrillation ablation, a leaflet from Southampton hospital in Britain says 2–4 hours, and a leaflet from Worcestershire hospital says about 3–4 hours. According to the Worcestershire leaflet, the person is usually awake during this, with local anesthesia and a sedative; sometimes general anesthesia is used.

According to MedlinePlus, pressure is applied to the catheter site, and you lie still for at least 1 hour, sometimes up to 5–6 hours. You go home the same day or the next day, and you need someone to take you. Over the next 2–3 days, there may be tiredness, an aching feeling in the chest, skipped beats or a fast, irregular heartbeat.

According to the Southampton leaflet, people usually return to everyday activities after going home, but they should not strain or lift heavy things for a few days.

MedlinePlus also lists rare complications: bleeding, blood clots, damage to an artery or valve, damage to a coronary artery, a fistula (an opening) between the esophagus and the atrium, tamponade (blood collecting around the heart and squeezing it), heart attack, and damage to the vagus nerve (involved in the work of the internal organs) or the phrenic nerve (which controls the diaphragm, a breathing muscle).

The figures below come from older or single-center data, so they do not show today's results precisely. The doctor gives your personal assessment.

• Schilling's 2002 review (the journal Heart). Success 95–99%, complications under 1%. The author himself wrote that some of the data were probably out of date. The risk of heart block (the signal not passing to the ventricles): 0.9% in AVNRT, 0.5% with an accessory pathway near the heart's septum, under 0.1% with a left-sided accessory pathway.
• Canadian Journal of Cardiology, 2007. One center's 14-year experience with 5330 patients. Success immediately after the procedure was 99% in AVNRT and 92% with an accessory pathway or flutter. Overall complications ranged from 1.06% to 2.1%, depending on the group.

These figures are examples taken from British hospital leaflets; the doctor gives your personal assessment. The Worcestershire leaflet explains ablation not as a complete cure, but as a way to get rid of the fibrillation or reduce it considerably.

• Results. Worcestershire: success depends on the type of fibrillation and other diseases, from 50% to about 80%. About 30% of people need a second ablation.
• The first weeks. Worcestershire: fibrillation in the first weeks does not mean failure. Southampton: for most people it takes about three months for symptoms to go away; if there is no result, the procedure may be repeated.
• Anticoagulant (blood thinner). According to the 2024 ESC guideline, it is continued for at least 2 months after ablation regardless of risk. The Southampton leaflet says it is important not to miss doses in the four weeks before the procedure.
• Risks (Worcestershire). Death up to 0.1% (1 in 1000); stroke about 1%; bleeding around the heart needing a tube to drain the fluid (a drain) about 1% (Southampton: 1–2%); damage to a blood vessel up to 1%; phrenic nerve damage 0.5%; damage to the heart's electrical system requiring a pacemaker about 1 in 500.