Strategy and Outcome of Catheter Ablation for Persistent Atrial Fibrillation　― Impact of Progress in the Mapping and Ablation Technologies ―

Abstract

ablation lesion. These novel technologies will promisingly bring new strategies of ablation and enhanced effectiveness and safety. Here, we review the previous reports on catheter ablation for persistent AF, and then introduce possible strategies for persistent AF ablation under concomitant use of the new technologies. Previous Reports on Ablation Strategies for Persistent AFPrior common procedures for persistent AF ablation include creation of linear lesions in the left atrium (LA) and focal ablation targeting complex fractionated electrograms (CFAEs Since the landmark study of Haïssaguerre et al demonstrating that the triggers initiating atrial fibrillation (AF) originate from the pulmonary veins (PVs), catheter ablation targeting PV has become an established strategy for paroxysmal AF. 1 The recognition that AF trigger sites were located within the PV antrum in the majority of cases led to extended, circumferential PV antrum isolation (PVAI) as an ablation procedure for AF. The recurrence of atrial tachyarrhythmias was reported to be significantly less in patients with large isolation areas around both ipsilateral PVs than in those with segmental PV isolation. 2 A recent study showed that, in patients with paroxysmal AF undergoing extended PVAI, the rate of late recurrence was lower than that previously reported with segmental or less extensive antral isolation. 3 Today, PVAI is the cornerstone of catheter-based therapies for paroxysmal AF. However, the success rates of catheter ablation in cases of persistent AF are significantly lower than those for paroxysmal AF. Progressive atrial remodeling in persistent AF has been regarded as a reason for the low efficacy of the treatment in persistent AF. Therefore, additional ablation strategies for modifying and eliminating the AF-sustaining atrial substrate have been developed and challenged.Recently, there has been technological progress in both 3D mapping systems and ablation catheters, which enable us to create precise high-resolution mapping and a durable Pulmonary vein (PV) antrum isolation (PVAI) is effective in treating paroxysmal atrial fibrillation (AF) but is less so for persistent AF. A recent randomized study on the ablation strategies for persistent AF demonstrated that 2 common atrial substrate modifications, creation of linear lesions in the left atrium and ablation of complex fractionated electrogram sites, in addition to PVAI did not improve the outcome compared with stand-alone PVAI, suggesting the necessity of a more individualized, selective approach to persistent AF. There are emerging technologies, including high-resolution mapping with the use of multi-electrode catheter and auto mapping system and contact force (CF) guide ablation; the former allows rapid and accurate confirmation of the completeness of PVAI, and the latter enhances the achievement of durable ablation lesions more securely. Ablation for fibrotic area(s) has been proposed as a new approach for substrate modification, and high-resolution mapping is useful to define the area ...

Important factors in left atrial posterior wall isolation using 28‐mm cryoballoon ablation for persistent atrial fibrillation—Block line or isolation area?

“…In the case of persistent AF, the effectiveness of PVI alone is limited, and additional ablation is often required . The left atrial posterior wall (LAPW) has been highlighted as another potential target area for isolation .…”

Catheter ablation for the management of atrial fibrillation: current technical perspectives

“…The effectiveness of PVI in patients with persistent and long-standing persistent AF has been reported as low as 21%. 31 The basis for these results is that the sites of AF initiation and maintenance may be diffuse in all four PVs and their antrum and conduction recurrence in only one PV can lead to AF recurrence. 32 The pathogenesis of persistent AF is complex and cannot be characterised by the same markers of paroxysmal AF (anisotropic conduction, autonomic innervation of the heart, embryogenesis of thoracic veins and interspersion of inhomogeneous tissue).…”

Serum-Soluble ST2 Is a Novel Biomarker for Evaluating Left Atrial Low-Voltage Zone in Paroxysmal Atrial Fibrillation

“…Radiofrequency catheter ablation (RFCA) has become first-line treatment for patients with paroxysmal atrial fibrillation (pAF) who are intolerant or refractory to antiarrhythmic medication [ 1 ]. AF recurrence is a major complication after RFCA.…”