Pulmonary Vein Isolation for Atrial Fibrillation

Key Points

Pulmonary vein isolation (PVI) is the cornerstone of current ablation techniques for the treatment of atrial fibrillation (AF).
Confirmation of electrical isolation with a circular mapping catheter is crucial to improve the short- and long-term outcomes of this procedure.
Wide antral PVI improves the long-term arrhythmia-free survival compared with ostial PVI.
PV reconnection is a major contributor to AF recurrences after PVI, especially in patients with paroxysmal AF.
Despite proven PVI, a subset of patients still experiences recurrent arrhythmia, mostly as a result of a higher prevalence of non-PV triggers.
PVI is associated with worse arrhythmia-free survival in patients with nonparoxysmal AF than those with paroxysmal AF

Pulmonary vein isolation (PVI) represents the cornerstone of current catheter ablation techniques for the treatment of atrial fibrillation (AF), with significantly improved efficacy compared with antiarrhythmic drug therapy as demonstrated in multiple randomized clinical trials. After the pivotal demonstration by Haïssaguerre and coworkers that focal discharges from the pulmonary veins (PVs) are implicated in the initiation of AF, empirical PVI has been performed with the highest procedural success in patients with paroxysmal AF, in whom spontaneous PV firing is frequently the only trigger for AF paroxysms. Over the years, PVI techniques have undergone a profound evolution, from initial attempts consisting of focal PV ablation of documented AF triggers within the PV, to the current standard of care, that is empirical ablation targeting the junction between the PVs and the left atrium (LA), and the PV antrum. To achieve PV antrum isolation, multiple approaches with different ablation strategies have been described; the technique currently endorsed by the HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of AF consists of antral PVI confirmed by a circular mapping catheter. In this chapter, the techniques and outcomes for different PVI techniques will be reviewed.

Patient Selection and Preprocedural Considerations

Indications for pulmonary vein isolation

Current guidelines for the management of AF give a class I indication with the highest level of evidence to PVI in patients with symptomatic paroxysmal AF, who have failed treatment with at least one class I or III antiarrhythmic drug (second-line treatment). Based on the results of randomized trials, PVI as first-line treatment in patients with no or minimal structural heart disease can be considered when performed in expert centers, where outcomes are comparable with antiarrhythmic drug (AAD) treatment, without an increase in complication rates. To date, there is no indication for PVI to reduce cardiovascular morbidity/mortality or hospitalization.

Antiarrhythmic Drugs

Patients undergoing PVI should have their antiarrhythmic drugs discontinued for at least five half-lives before the ablation procedure to facilitate the identification of AF triggers, especially those outside the PVs that are not empirically targeted. In this regard, although adequate drug washout can be achieved in reasonable time before the procedure for most AADs, patients receiving chronic treatment with amiodarone represent a unique challenge because of the long half-life of the drug, and thus require longer elimination time. There might be an incremental benefit of adequate preprocedural amiodarone wash-out, suggesting that discontinuation of the drug 4 to 6 months before the procedure increases the chance of disclosing latent non-PV trigger sites, resulting in better long-term arrhythmia-free survival.

Anticoagulation Status

A proper anticoagulation status is crucial to minimize the risk of periprocedural thromboembolism and bleeding. In recent times, a substantial body of evidence has been built on the benefit of performing PVI under uninterrupted anticoagulation with both warfarin and the novel oral anticoagulants; this reduces the risk of stroke without increasing the risk of bleeding. Of note, among the novel oral anticoagulants, our experience with uninterrupted dabigatran has been disappointing, with an increase in the risk of bleeding or thromboembolic complications compared with uninterrupted warfarin; therefore we usually prefer to use warfarin or factor Xa inhibitors in the periablation setting. Another important strategy to minimize the risk of periprocedural stroke is to administer an intravenous heparin bolus (usually 100 U per kg up to 10.000 U with warfarin, or 12.000 to 15.000 U with factor Xa inhibitors) right after vascular access is obtained. The goal is to achieve full anticoagulation (goal activated clotting time [ACT] 350–500 seconds) before transseptal access, thus reducing the chance of thrombus formation when sheaths and catheters are in the LA.

Anesthesia Protocol

The anesthesia protocol adopted during PVI can also affect the procedural results. Although moderate to deep sedation/anesthesia can be employed, general anesthesia, with or without high-frequency jet ventilation, has the important advantage of controlling respiration by eliminating deep breathing. This improves catheter stability, leading to more effective RF energy delivery, thus reducing procedural times and improving long-term outcomes compared with conscious sedation.

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