Ultra-high-resolution assessment of lesion extension after cryoballoon ablation for pulmonary vein isolation

Abstract

IntroductionUnrecognized incomplete pulmonary vein (PV) isolation during the index procedure, can be a major cause of clinical recurrences of atrial fibrillation (AF) after cryoballoon (CB) ablation. We aimed to characterize the extension of the lesions produced by CB ablation and to assess the value of using an ultra-high resolution electroanatomic mapping (UHDM) system to detect incomplete CB lesions.Materials and methodsTwenty-nine consecutive patients from the CHARISMA registry undergoing AF ablation at four Italian centers were prospectively evaluated. The Rhythmia™ mapping system and the Orion™ (Boston Scientific) mapping catheter were used to systematically map the left atrium and PVs before and after cryoablation.ResultsA total of 116 PVs were targeted and isolated. Quantitative assessment of the lesions revealed a significant reduction of the antral surface area of the PV, resulting in an ablated area of 5.7 ± 0.7 cm2 and 5.1 ± 0.8 cm2 for the left PV pair and right PV pair, respectively (p = 0.0068). The mean posterior wall (PW) area was 22.9 ± 2 cm2 and, following PV isolation, 44.8 ± 6% of the PW area was ablated. After CB ablation, complete isolation of each PV was documented by the POLARMap™ catheter in all patients. By contrast, confirmatory UHDM and the Lumipoint™ tool unveiled PV signals in 1 out of 114 of the PVs (0.9%). Over 30-day follow-up, no major procedure-related adverse events were reported. After a mean follow-up of 333 days, 89.7% of patients were free from arrhythmia recurrence.ConclusionThe lesion extension achieved by the new CB ablation system involved the PV antrum, with less than 50% of the PW remaining untouched. The new system, with short tip and circular mapping catheter, failed to achieve PV isolation in only 0.9% of all PVs treated.Clinical trial registration[http://clinicaltrials.gov/], identifier [NCT03793998].

Pulsed field ablation technology for pulmonary vein and left atrial posterior wall isolation in patients with persistent atrial fibrillation

“…Electrograms with voltages above 0.5 mV were considered to indicate healthy and unablated tissue, while electrograms with voltages less than 0.2 mV were deemed to indicate dense scar tissue. Points with voltages between 0.2 and 0.5 mV were defined as indicating damaged but viable tissue 19,20 . Postablation remapping was carried out during coronary sinus pacing, to accurately pinpoint any conduction gaps in the ablation lines.…”

“…Detailed locations of residual PV connections are reported in Figure 3A. deliveries to achieve PVI were comparable among the procedural approaches (17 [14][15][16][17][18][19][20][21][22] vs. 17 [13][14][15][16][17][18][19][20][21][22][23][24] mins for fluoroscopy time, p = 0.741 and 32 [32][33][34] vs. 32 [32][33][34][35][36][37][38][39][40] mins for number of PFA deliveries to achieve PVI, p = 0.055, respectively).…”

“…Points with voltages between 0.2 and 0.5 mV were defined as indicating damaged but viable tissue. 19,20 Postablation remapping was carried out during coronary sinus pacing, to accurately pinpoint any conduction gaps in the ablation lines. (Figure 2) The LAPW surface was defined as the area between the PV lesions on the PW bordered on the supero-inferior aspect by two lines connecting the most superior and inferior points of the circumferential PV lesions (Supporting Information: Figure 1).…”