What is atrial fibrillation ablation?

Atrial fibrillation ablation is an invasive electrophysiology procedure performed using catheters introduced into the heart through the venous system. In most patients, the main objective is pulmonary vein isolation (PVI). The pulmonary veins are a major source of the abnormal electrical impulses that can initiate and maintain atrial fibrillation. During the procedure, controlled lesions are created around the pulmonary veins to electrically disconnect them from the left atrium. Depending on the type of atrial fibrillation and the individual atrial substrate, the ablation strategy may be further personalised.

When is atrial fibrillation ablation recommended?
Ablation is not necessary for every patient with atrial fibrillation. The decision is individualised according to the type of atrial fibrillation, symptom burden, age and general health, associated cardiovascular conditions, left atrial characteristics, response or intolerance to antiarrhythmic drugs and patient preference. It is particularly considered in patients with symptomatic and recurrent atrial fibrillation events, especially when drug therapy is ineffective or poorly tolerated.
In selected patients with symptomatic paroxysmal atrial fibrillation, current guidelines also support catheter ablation as a possible first-line rhythm-control treatment, without necessarily requiring previous failure of an antiarrhythmic drug. In persistent atrial fibrillation, the decision is generally more individualised. [1,2]

How is the procedure performed?
Atrial fibrillation ablation is performed in an electrophysiology laboratory. One or more catheters are introduced through the femoral veins and advanced to the heart. In my procedural practice, femoral venous access is performed under ultrasound and/or radioscopic guidance. After reaching the left atrium through a transseptal puncture, the anatomy and electrical activity of the left atrium and pulmonary veins are assessed. The pulmonary veins are then electrically isolated using the ablation technology considered most appropriate for the individual patient.

Sedation or general anaesthesia?
Atrial fibrillation ablation can be performed under sedation or general anaesthesia. The choice depends on the ablation technology, the clinical characteristics of the patient and the anaesthetic protocol used. With some PFA systems, deep sedation or general anaesthesia is frequently preferred to optimise patient comfort and procedural stability.

Pulsed Field Ablation (PFA) is a reduced thermal ablation technology that uses very short, high-intensity electrical pulses. These electrical fields produce irreversible electroporation that leads to programmed death of myocardial cell membranes, creating controlled cardiac tissue lesions without relying primarily on heat or freezing.
One of the main features of PFA is the increased sensitivity of myocardial tissue to the electrical fields used. Compared with thermal ablation, this can reduce injury to surrounding structures such as the oesophagus, pulmonary veins and phrenic nerve.
The 2026 international scientific statement on PFA describes it as an important evolution in atrial fibrillation ablation. Randomised trials have shown efficacy comparable to conventional thermal ablation, with generally shorter procedure times and a favourable profile for some collateral tissue injuries. [3,4]

PFA or radiofrequency: which technique is better?
There is no single ablation technology that is best for every patient. PFA and radiofrequency use different mechanisms, but both can effectively achieve pulmonary vein isolation. As noted above, Pulsed Field Ablation uses high-intensity electrical fields and produces irreversible electroporation. It is predominantly non-thermal and is generally associated with shorter procedural times and a favourable safety profile regarding some extracardiac structures.
Radiofrequency ablation uses thermal energy to create controlled lesions in cardiac tissue. It has more than three decades of clinical experience and provides considerable flexibility when personalised lesion sets or additional atrial targets are required.
Current evidence indicates that PFA can achieve clinical outcomes comparable to conventional thermal ablation for atrial fibrillation. The choice between PFA and radiofrequency therefore depends on the type of atrial fibrillation, anatomy, atrial substrate, additional ablation targets and the overall procedural strategy. [3,4]

PFA in paroxysmal and persistent atrial fibrillation
The most established evidence for PFA concerns paroxysmal atrial fibrillation, in which pulmonary vein isolation is generally the main ablation target. PFA is also increasingly used in persistent atrial fibrillation. In patients with relatively limited atrial remodelling, pulmonary vein isolation alone may still represent an appropriate strategy.
In more advanced persistent atrial fibrillation, the optimal approach may need to be more personalised, and the role of additional ablation targets beyond the pulmonary veins continues to evolve.

How effective is atrial fibrillation ablation?
The objective of ablation is to significantly reduce arrhythmia recurrences and overall AF burden, improve symptoms and quality of life.
The probability of success depends on several factors, including:

• paroxysmal versus persistent atrial fibrillation;

• duration of atrial fibrillation;

• left atrial size and remodelling;

• obesity;

• obstructive sleep apnoea;

• hypertension;

• alcohol consumption;

• other cardiovascular and systemic conditions.

Some patients may experience recurrent atrial fibrillation and, in selected cases, a repeat ablation procedure may be appropriate.
In major contemporary PFA studies, approximately 80% of patients with paroxysmal atrial fibrillation were free from recurrent atrial arrhythmias at one year after a single procedure. Outcomes in persistent atrial fibrillation are generally lower, approximately 65–70% at one year. These percentages vary according to patient characteristics, ablation technology, the definition of treatment success and the intensity of rhythm monitoring. [3,5,6]

What are the risks of atrial fibrillation ablation?
Atrial fibrillation ablation is a well-established procedure, but, like any invasive cardiac intervention, it carries potential risks. Possible complications include vascular complications at the femoral access site, pericardial effusion or cardiac tamponade, thromboembolic events or stroke, and other complications related to catheter manipulation and left atrial access. Thermal ablation techniques also carry very rare but potentially important risks such as oesophageal injury, pulmonary vein stenosis and phrenic nerve injury. PFA has demonstrated a particularly favourable profile regarding several forms of collateral extracardiac injury. However, it is not completely risk-free. Complications common to all catheter procedures remain possible, and PFA-specific events such as coronary spasm and haemolysis have also been reported. Rare cases of haemolysis-related acute kidney injury have been described. The overall safety profile depends on the technology used, patient characteristics and the experience of the electrophysiology team. [3]

How long does the procedure take and how long is the hospital stay?
Procedure time varies depending on the ablation technology used and the complexity of the individual case. In general, atrial fibrillation ablation may take approximately one to three hours, although some PFA procedures can be considerably shorter. Contemporary studies consistently show shorter procedural times with PFA compared with conventional thermal techniques. [3] After an uncomplicated procedure, hospital observation is usually relatively short and many patients are discharged the following day. In selected patients and centres using dedicated protocols, same-day discharge may also be possible.

What happens after atrial fibrillation ablation?
A follow-up electrophysiology assessment is arranged after the procedure. During the first weeks, transient palpitations or brief episodes of atrial arrhythmia may occur and do not necessarily indicate that the ablation has failed. Follow-up may include ECG, Holter monitoring or other rhythm-monitoring systems depending on the clinical situation. The 2024 international expert consensus recommends an 8-week blanking period after atrial fibrillation ablation, during which early recurrences are not automatically considered treatment failure. [2] 

Can anticoagulation be stopped after ablation?
Not automatically. Therapeutic anticoagulation is generally continued for at least two months after atrial fibrillation ablation. After this period, whether anticoagulation should be continued or discontinued depends mainly on the individual risk of stroke and systemic thromboembolism, rather than simply on whether the ablation appears to have eliminated atrial fibrillation. [2]

Atrial fibrillation ablation in Florence