Evolving Strategies in Catheter Ablation of Long-Standing Atrial Fibrillation

Abstract

Since its original description in 1998, the technique of catheter-based atrial fibrillation (AF) ablation has undergone several modifications.1 Currently, many operators use an anatomic approach, consisting of circumferential lesions encircling individual or ipsilateral pulmonary veins (PVs), with additional empirical left atrial ablations (lines), whereas others perform a more PV-specific approach, using entrance and exit block to validate isolation, deferring any additional non-PV lesions, unless clinically indicated.2–7 Despite these differences in technique, there remain remarkable consistencies in the AF outcome data between centers, with overall single-procedure efficacy of ≥70% in achieving long-term arrhythmia control for patients with paroxysmal AF but significantly lower success rates in achieving a similar outcome for patients with persistent or permanent AF. The obvious implications of these observations are that the mechanisms underlying initiation and maintenance of persistent or permanent AF may extend beyond PVs. Although this remains an area of active discussion and debate, it has nevertheless prompted investigators to explore more extensive ablation strategies in these patients.8–10 Article see p 344 Consistent with this trend, in this issue of Circulation: Arrhythmia and Electrophysiology , Rostock et al11 report their observations in patients with chronic AF. This was a single-center observational study in which 88 subjects underwent ablation during AF, using a step-wise approach comprising PV isolation followed by extensive left atrial, coronary sinus, and right atrial ablation, targeting areas manifesting continuous or rapid electric activity, local activation gradients, or centrifugal activation patterns. The end point of lesion creation was alteration in local electrogram characteristics, and the procedure end point was restoration of sinus rhythm, unless procedure duration exceeded 6 hours or the patient received ≥5 L of fluid, in which case AF was cardioverted. Patients were subsequently followed closely, with frequent Holter monitoring and clinic visits. Reablation was the preferred treatment …