Quantitative Analysis of the Isolation Area During the Chronic Phase After a 28-mm Second-Generation Cryoballoon Ablation Demarcated by High-Resolution Electroanatomic Mapping

Abstract

Background-The post-second-generation cryoballoon (CB) ablation isolation area during the chronic phase has not been described. The aim of this study was to quantitatively evaluate the chronic-phase isolation area after 28-mm secondgeneration CB ablation and compare it to the estimated conventional radiofrequency circumferential pulmonary vein isolation (CPVI) line. Methods and Results-Thirty-two patients with paroxysmal atrial fibrillation underwent pulmonary vein (PV) isolation using second-generation CB. After a median of 6.0 (4.0-9.0) months, the PV isolation area was evaluated using highresolution mapping (1-mm electrode, 2-mm interelectrode spacing; 527±99 points per map) and pacing techniques in all patients (17 with and 15 without arrhythmia recurrence beyond blanking period) and compared with estimated conventional radiofrequency CPVI area. PV reconnections were observed in 34 of 126 PVs (27.0%) among 21 of 32 patients (65.6%), which were eliminated by a median of 1.0 (1.0-3.0) focal radiofrequency application. The left-and right-sided PV antrum isolation area and nonablated posterior wall areas were 9.8±1.7, 8.1±2.3, and 17.0±6.1 cm 2 , respectively. The cryoablated areas were significantly smaller than the estimated conventional radiofrequency CPVI areas in all but the right inferior PV. The difference was highest in the left superior PV. In 2 patients (6.3%), recurrent atrial fibrillation originated from the foci identified at the left superior PV antrum outside the CB isolation area but inside the estimated conventional radiofrequency CPVI line. Conclusions-Although the PV isolation areas during the chronic phase after the second-generation CB ablation were generally wide, they were significantly smaller than the area encircled by the CPVI line except at the right inferior PV antrum. Recurrent atrial fibrillation could originate from the left superior PV antrum and could be isolated by a CPVI but not by a CB. (Circ Arrhythm Electrophysiol. 2016;9:e003879.

Dormant Conduction after Second-Generation Cryoballoon-Mediated Pulmonary Vein Isolation for Atrial Fibrillation: Comparison with Contact Force-guided Irrigated-Tip Radiofrequency Ablation

“…Second, repeat procedures were not analyzed to assess long-term durability of the PVI. Although some differenc-es can be expected in the chronic phase, the trends should be similar to those in the acute phase 28,29) .…”

“…Recent studies comparing CF-guided RFA with CBA have shown statistical equivalence between the 2 technologies 25) . This may relate to the fact that even focused lesions may eliminate triggers and that not for all transmural continuous lesions around the PVs are needed [26][27][28][29] .…”

Effect of Cryoballoon Ablation vs. Radiofrequency Ablation on Left Atrial Ganglionated Plexi in Patients with Atrial Fibrillation

“…A previous study showed the posterior left atrial (LA) wall area isolated by CBA to be wide and antral, and the resulting debulking of this area, in addition to discrete PVI, was thought to explain, at least in part, the efficacy of CBA 7) . However, a more recent study showed the PV antral area isolated by CBA to be significantly smaller than the circumferential PV area isolated by RFA 8) . The intrinsic cardiac autonomic nervous system (i.e., the ganglionated plexi [GPs]) has been thought to contribute to the AF substrate and specifically to the initiation and persistence of AF [9][10][11] .…”

Differences in the electrophysiological findings of repeat ablation between patients who first underwent cryoballoon ablation and radiofrequency catheter ablation for paroxysmal atrial fibrillation

“…A three‐dimensional mapping system was used as a reference to determine the location of the circular mapping catheter to identify the PV reconnection site and to measure the isolation area before starting repeat ablation (Figure ). The isolated surface areas of each PV antrum and ipsilateral PV antrum were calculated …”

“…However, large PVs will allow the advancement of the CB distally while the PV roof, antrum, and left atrial anterior/posterior wall near the PV junction remain intact. This means that CB ablation isolates a limited PV area . We hypothesized that a wide ablation area will eliminate more arrhythmic foci and lead to better outcomes.…”