Charge density mapping demonstrates superiority in catheter ablation of post-surgical atrial tachycardias.

Introduction: Atrial tachycardia (AT) frequently occurs after cardiac surgery or surgical ablation procedures. The novel charge density-based mapping system (CDM) provides global chamber mapping and can detect crucial pathways of conduction; therefore, it has potential added value in catheter ablation (CA) of post-surgical ATs. We aimed to test the hypothesis that CDM-guided CA procedures are safe, feasible, and may improve outcome compared to conventional sequential 3D mapping (CARTO)-based CA. Methods and results: Consecutive patients undergoing CA for post-surgical AT guided by CDM or CARTO were enrolled. Procedural safety and efficiency were analyzed. Acute success, one-year outcome was assessed. A total of 35 patients (mean age 60.8 ± 10.6 years, 42.9% female) underwent CA of AT using CDM (n = 20) and CARTO (n = 15). A total of 61 ATs were mapped (35 in CDM and 26 in CARTO group). Four patients had focal ATs, 22 macro re-entrant, and 8 patients had ATs with both mechanisms. No differences were found in procedural complication (CDM 3 vs. CARTO 1 patient, p = 0.61). There were no differences in procedure duration (185.9 vs. 147.9 min, p = 0.09), fluoroscopy dose (165.0 vs. 155.0 mGy, p = 0.31), RF application number (28.0 vs. 18.0, p = 0.17) or duration (1,251.5 vs. 1,060.0 s, p = 0.54). Acute success was 95.0% in CDM and 73.3% in CARTO group (p = 0.14). Cumulative AT recurrence rates were lower in CDM group compared to CARTO group (10.0% vs. 46.7%, p = 0.02). Conclusions: The CDM system is feasible. Our data suggest that patients treated with CDM-guided CA developed fewer AT recurrences as compared to CARTO-guided procedures.

Atrial Fibrillation Global Changes after Pulmonary Vein and Posterior Wall Isolation: A Charge Density Mapping Study.

BACKGROUND: Non-contact charge density (CD) mapping allows a global visualization of left atrium (LA) activation and of activation patterns during atrial fibrillation (AF). The aim of this study was to analyze, with CD mapping, the changes in persistent AF induced by pulmonary vein isolation (PVI) and LA posterior wall isolation (LAPWI). METHODS: Patients undergoing PVI + LAPWI using the Arctic Front Advance PROTM cryoballoon system were included in the study. CD maps were created during AF at baseline, after PVI and after LAPWI. Three distinct activation patterns were identified in the CD maps: localized irregular activation (LIA), localized rotational activation (LRA) and focal centrifugal activation (FCA). LA maps were divided into the following regions: anterior, septal, lateral, roof, posterior, inferior. RESULTS: Eleven patients were included, with a total of 33 maps and 198 AF regions analyzed. Global and regional AF cycle lengths significantly increased after PVI and LAPWI. Baseline analysis demonstrated higher LIA, LRA and FCA numbers in the posterior and anterior regions. After PVI, there was no change in LIA, LRA and FCA occurrence. After PVI + LAPWI, a significant decrease in LRA was observed with no difference in LIA and FCA occurrence. In the regional analysis, there was a significant reduction in the LIA number in the inferior region, in the LRA number in the roof and posterior regions and in the FCA number in the lateral region. CONCLUSIONS: A global reduction in the LRA number was observed only after PVI + LAPWI; it was driven by a reduction in rotational activity in the roof and posterior regions.

Less Pulmonary Vein Reconnection at Redo Procedures Following Radiofrequency Point-by-Point Antral Pulmonary Vein Isolation With the Use of Contemporary Catheter Ablation Technologies.

OBJECTIVES: This study investigated whether real-world use of contemporary technologies changed pulmonary vein (PV) reconnection and redo pulmonary vein isolation (PVI) procedure frequencies. BACKGROUND: Previous studies consistently reported that following PVI recurrence of PV conduction is observed in >80% of patients. METHODS: Consecutive patients undergoing 529 first and/or redo radiofrequency point-by-point PVI between January 2013 and December 2016 were included. RESULTS: Between 2013 and 2016, redo PVI rate in atrial fibrillation significantly decreased (p < 0.001); in ≤12 months, first redo PVI rate decreased from 19% to 4%. The percentage of patients having PV reconnection at second PVI significantly decreased from 90% to 29% (p = 0.001). One PVI was performed in 393 and >1 in 79 patients. Female sex was associated with >1 PVI (hazard ratio [HR]: 1.86; 95% confidence interval [CI]: 1.10 to 3.13; p = 0.02). Sixty patients underwent first and second PVI in the study period. Female sex (HR: 2.79; 95% CI: 1.67 to 4.64; p < 0.001) and left atrial diameter (HR: 1.05; 95% CI: 1.01 to 1.08; p = 0.01) were associated with more and use of automatic ablation annotation algorithm during first PVI with fewer (HR: 0.54; 95% CI: 0.32 to 0.92; p = 0.02) redo PVI procedures. In 31 of 60 patients, ≥1 PV was reconnected at second PVI. The need for "touch-up" applications at the first PVI was the only predictor of PV reconnection. CONCLUSIONS: Redo rate in atrial fibrillation and PV reconnection at redo PVI significantly decreased in recent years. Male sex, left atrial diameter, and use of automatic ablation annotation algorithm at first PVI were associated with fewer redo procedures. First-pass isolation was associated with lower PV reconnection rate at second procedure. Female sex was associated with more redo procedures but not higher PV reconnection frequencies.

Validating Left Atrial Low Voltage Areas During Atrial Fibrillation and Atrial Flutter Using Multielectrode Automated Electroanatomic Mapping.

OBJECTIVES: This study aimed: 1) to determine the voltage correlation between sinus rhythm (SR) and atrial fibrillation (AF)/atrial flutter (AFL) using multielectrode fast automated mapping; 2) to identify a bipolar voltage cutoff for scar and/or low voltage areas (LVAs); and 3) to examine the reproducibility of voltage mapping in AF. BACKGROUND: It is unclear if bipolar voltage cutoffs should be adjusted depending on the rhythm and/or area being mapped. METHODS: High-density mapping was performed first in SR and afterward in induced AF/AFL. In some patients, 2 maps were performed during AF. Maps were combined to create a new one. Points of <1 mm difference were analyzed. Correlation was explored with scatterplots and agreement analysis was assessed with Bland-Altman plots. The generalized additive model was also applied. RESULTS: A total of 2,002 paired-points were obtained. A cutoff of 0.35 mV in AFL predicted a sinus voltage of 0.5 mV (95% confidence interval [CI]: 0.12 to 2.02) and of 0.24 mV in AF (95% CI: 0.11 to 2.18; specificity [SP]: 0.94 and 0.96; sensitivity [SE]: 0.85 and 0.75, respectively). When generalized additive models were used, a cutoff of 0.38 mV was used for AFL for predicting a minimum value of 0.5 mV in SR (95% CI: 0.5 to 1.6; SP: 0.94, SE: 0.88) and of 0.31 mV for AF (95% CI: 0.5 to 1.2; SP: 0.95, SE: 0.82). With regard to AF maps, there was no change in the classification of any left atrial region other than the roof. CONCLUSIONS: It is possible to establish new cutoffs for AFL and/or AF with acceptable validity in predicting a sinus voltage of <0.5 mV. Multielectrode fast automated mapping in AFL and/or AF seems to be reliable and reproducible when classifying LVAs. These observations have clinical implications for left atrial voltage distribution and in procedures in which scar distribution is used to guide pulmonary vein isolation and/or re-isolation.

Superior efficacy of pulmonary vein isolation with online contact force measurement persists after the learning period: a prospective case control study.

PURPOSE: Use of online contact force (CF) measurement during circumferential pulmonary vein (PV) isolation (CPVI) for atrial fibrillation (AF) has demonstrated improvements in procedural parameters and mid-term clinical outcome. However, it is unknown if experience gained with CF measuring catheters improves the efficacy of subsequent CPVI procedures performed without CF measurement. METHODS: This prospective trial compared procedural results of CPVI performed without a CF measuring catheter to a control group performed with a CF measuring catheter, by an operator with prior experience with CF technology.. RESULTS: Thirty-six eligible paroxysmal (n = 27) or persistent (n = 9) AF patients were consecutively enrolled. Twelve patients underwent CPVI with the non-CF catheter (CF- group) in a recall period and 24 with the CF catheter (CF+ group). After the first circumferential lesion set, the number of PV pairs requiring additional touch-up lesions to achieve electrical isolation was significantly less in the CF+ group (2 of 48 (4.2 %) vs. 7 of 24 (29.2 %) in the CF+ and CF- groups, respectively, p = 0.005). The procedure time was significantly lower in the CF+ group (117.9 ± 23.3 vs. 134.1 ± 25.3 min, p = 0.033). Radiofrequency (RF) and fluoroscopy time did not differ between groups (31.5 ± 7.1 vs. 31.8 ± 7.0 min and 11.8 ± 5.6 vs. 11.0 ± 5.8 min in the CF+ and the CF- group, respectively) CONCLUSIONS: With the use of online CF measurement, PV isolation is more frequently complete following the first circumferential lesion set. A previous learning period with direct CF feedback is not a substitute for real-time direct CF measurement to maintain this advantage.