Noninvasive Panoramic Mapping of Human Atrial Fibrillation Mechanisms: A Feasibility Report

BackgroundEffects of nonparoxysmal atrial fibrillation (non‐PAF) ablation _targeting complex fractionated atrial electrogram (CFAE) areas and/or low voltage areas (LVAs) are still controversial.Methods and ResultsA recently developed online real‐time phase mapping system (ExTRa Mapping) was used to conduct LVA mapping and simultaneous ExTRa and CFAE mapping in 28 non‐PAF patients after pulmonary vein isolation (PVI). Nonpassively activated areas, in the form of meandering rotors and/or multiple wavelets assumed to contain non‐PAF drivers, partly overlapped with CFAE/LVAs but not always coincided with them.ConclusionReal‐time rotor imaging, rather than conventional indirect indicators only, might be very useful for detecting non‐PAF drivers.

BACKGROUND:Clinical outcomes after ablation of persistent atrial fibrillation remain suboptimal. Identification of AF drivers using a novel integrated mapping technique may be crucial to ameliorate the clinical outcome. METHODS AND RESULTS:Persistent AF patients were prospectively enrolled to undergo high-density electrophysiological mapping to identify repetitive-regular activities (RRas) before modified circumferential pulmonary vein (PV) ablation. They have been randomly assigned (1:1 ratio) to ablation of RRa followed by modified circumferential PV ablation (mapping group; n=41) or modified circumferential PV ablation alone (control group; n=40). The primary end point was freedom from arrhythmic recurrences at 1 year. In total, 81 persistent AF patients (74% male; mean age, 61.7±10.6 years) underwent mapping/ablation procedure. The regions exhibiting RRa were 479 in 81 patients (5.9±2.4 RRa per patient): 232 regions in the mapping group (n=41) and 247 in the control group (n=40). Overall, 185 of 479 (39%) RRas were identified within the PVs, whereas 294 of 479 (61%) in non-PV regions. Mappingguided ablation resulted in higher arrhythmia termination rate when compared with conventional strategy (25/41, 61% versus 12/40, 30%; P<0.007). Total radiofrequency duration (P=0.38), mapping (P=0.46), and fluoroscopy times (P=0.69) were not significantly different between the groups. No major procedure-related adverse events occurred. After 1 year, 73.2% of mapping group patients were free from recurrences versus 50% of control group (P=0.03). CONCLUSIONS:_targeted ablation of regions showing RRa provided an adjunctive benefit in terms of arrhythmia freedom at 1-year follow-up in the treatment of persistent AF. These findings might support a patienttailored strategy in subjects with nonparoxysmal AF and should be confirmed by additional larger, randomized, multicenter studies.

Since the first catheter ablation for cardiac arrhythmia more than three decades ago, ablation technology has continually evolved at a rapid pace. Much of the early progress in the field was made in ablation of supraventricular tachycardias. Following a seminal study from Haïssaguerre et al. 1 in 1998, which demonstrated that pulmonary vein triggers are important sources of atrial fibrillation (AF), the approach to management of AF underwent a revolution. Electrical isolation of pulmonary veins (PVs) using catheter ablation became an established therapeutic strategy in patients with paroxysmal AF. During subsequent years, the role of ablation in AF expanded, and more extensive strategies involving ablation of non-pulmonary vein triggers and modification of the left atrial substrate were demonstrated to be effective, even in persistent forms of AF. New Technologies and Techniques for AF AblationCurrently, the most widely used technique for PV isolation involves delivery of point-by-point ablation lesions around the circumference of the vein. A number of different variations to the approach have been developed. During the early stages of PV isolation, a 'segmental approach' which involved _targeting the earliest PV potentials at the ostium of the PV was commonly used. Due to high reconnection rates and the risk of PV stenosis, the technique has progressively been modified and the prevailing technique involves circumferential antral ablation to achieve PV isolation. AbstractCatheter ablation is an established treatment strategy for a range of different cardiac arrhythmias. Over the past decade two major areas of expansion have been ablation of atrial fibrillation (AF) and ventricular tachycardia (VT) in the context of structurally abnormal hearts. In parallel with the expanding role of catheter ablation for AF and VT, multiple novel technologies have been developed which aim to increase safety and procedural success. Areas of development include novel catheter designs, novel navigation technologies and higher resolution imaging techniques. The aim of the present review is to provide an overview of novel developments in AF ablation and VT ablation in patients with of structural cardiac diseases.