Relationship between atrial scar on cardiac magnetic resonance and pulmonary vein reconnection after catheter ablation for paroxysmal atrial fibrillation

Abstract

Introduction Pulmonary vein (PV) reconnection is frequent in patients showing atrial fibrillation (AF) recurrence after PV isolation (PVI). Its detection with cardiac magnetic resonance (CMR) may help predict outcome and guide redo procedures. We assessed the relationship between scar on CMR and PV reconnection after catheter ablation for paroxysmal AF. Methods and Results Fifty‐one patients with paroxysmal AF underwent CMR before PVI using either a conventional single‐electrode catheter (N = 28) or a circular multielectrode catheter (N = 23). At 3 months, a second CMR study was performed, followed by a systematic electrophysiological procedure to look for PV reconnection, regardless of AF recurrence. Preablation fibrosis and postablation scar were quantified and mapped from late gadolinium‐enhanced CMR. CMR results were compared to the distribution and extent of PV reconnection. CMR and electrophysiological findings were compared between catheter types. Three months after successful PVI, scar gaps were found in 39 (76%) patients, and 78 (39%) veins. Electrical PV reconnection was detected in 45 (88%) patients, and 99 (50%) veins. The extent of PV reconnection related closely to the number of gaps (R = 0.55; P < .001), and to scar burden (R = −0.63; P < .001). However, the agreement was only fair for the localization of PV reconnection (k = 0.37; P < .001), scar gaps particularly lacking sensitivity in areas of pre‐existing fibrosis. The circular catheter was associated with shorter procedures (P < .001), more scar (P = .01), less gaps (P = .01), and less reconnected veins (P = .03). Conclusion PV reconnection is extremely frequent after PVI. CMR scar imaging accurately predicts its extent, but poorly predicts its location. Multielectrode circular catheters induce more complete ablation.

Impact of cryoballoon applications on lesion gaps detected by magnetic resonance after pulmonary vein isolation

“…Characterization of postablation lesions may also have therapeutic implications. In those patients undergoing redo procedures, identification of ablation gaps in LGE‐CMR localizes electrical reconnections and may simplify ablation, 12 although some groups failed to prove concordance between electrical and LGE‐CMR gaps 24 . Overall, the visualization of ablation lesions in the LA evolves as a useful tool in the prognostic and therapeutic approach for AF patients undergoing ablation.…”

Pulmonary vein reconnection following cryo-ablation: Mind the “Gap” in the carinae and the left atrial appendage ridge

“…However, the prevalence of non-PV triggers remains low at least for patients with paroxysmal AF; non-PV triggers more commonly characterize patients with non-paroxysmal AF [26]. Although investigators have claimed that single-shot techniques, such as those using circular multielectrode catheters [27], or cryoballoons afford fewer scar gaps compared to point-by-point RF ablation method [13,28], this needs to be further confirmed in comparative studies. Others have reported fewer reconnection gaps in the left or both-sided PVs with use of newer generation balloons compared with old-generation balloons [6,29].…”

Ablation Lesion Assessment with MRI

“…[ 5 – 7 ] However, it should be emphasised that various other methods using distinct internal references and thresholds have been validated ( Table 1 ). [ 17 , 39 , 50 , 51 ]…”