Single accessory pathway with multiple insertions? First-in-human 3D visualization using dipole charge density mapping: a case report.

Background: Accessory pathways (APs) with multiple atrial insertions are often unrecognized and associated with initial catheter ablation (CA) failure. Recently, a novel dipole charge density mapping (DCDM) system was developed that allows mapping of complex arrhythmias based on a single beat. We aim to present the first-in-human report of 3D visualization of a single AP with two atrial insertion sites using high-resolution DCDM. Case summary: A 43-year-old man with recurrent symptomatic atrioventricular re-entrant tachycardia and previously failed CA attempts underwent repeated CA using DCDM. Dipole charge density mapping identified two quasi-simultaneous early atrial activation sites at the left lateral and left anterolateral atrial aspects of the mitral annulus, suggesting the presence of a single AP with dual atrial insertion sites. Successful radiofrequency CA was performed at the mid-body of the AP. Discussion: The true prevalence of APs with multiple atrial insertion sites may be higher than currently reported. This is the first-in-human report of 3D visualization of a single AP with two atrial insertion sites using high-resolution DCDM. Dipole charge density mapping allows the accurate localization of APs with multiple insertion sites based on a single beat.

Electrographic flow mapping guided catheter ablation offers advantages for patients with persistent atrial fibrillation.

BACKGROUND: Catheter ablation (CA) remains challenging due to suboptimal success rates in persistent atrial fibrillation (AF). Existing mapping technologies cannot reliably distinguish sources in this patient population. Recently, the novel electrographic flow (EGF) mapping system was developed using a modified Horn-Schunk optical flow algorithm to detect and quantify patterns of electrical wavefront propagation in the atria. OBJECTIVES: To test the hypothesis that targeted source ablation based on EGF mapping is superior to empiric AF ablation. METHODS: We included all consecutive patients undergoing EGF guided ablation for persistent AF. All patients underwent pulmonary vein isolation (PVI) and were treated with the same EAM system (CARTO). The outcome of PVI+EGF guided CA was compared with data of PVI-only procedures (PVI-only group) and PVI plus additional empiric adjunctive linear and substrate ablations (PVI+LINES group). 12-months outcome as freedom from AF and atrial tachycardia/flutter (AT/AFL), procedural safety and efficiency characterized by procedure duration, fluoroscopy use, radiofrequency applications and duration, were analyzed. Both intention-to-treat and per protocol analysis were conducted. RESULTS: A total number of 70 patients (39 in PVI+EGF, 16 in PVI-only and 15 patients in PVI+LINES group) were enrolled. Intention-to-treat analysis showed fewer AF recurrences in PVI+EGF as compared with the PVI-only or PVI+LINES groups at 12 months (25.6% vs. 62.5% vs. 53.3%, p = .02). There were no differences in AT/AFL recurrence (17.9% vs. 37.5% vs. 20.0%, p = .37). Procedure times were longer in PVI+EGF group (p < .01), and there were no differences in fluoroscopy use (p = .67). CONCLUSION: Our data suggest that patients treated with EGF-guided CA developed fewer AF recurrences. Although the procedure times are longer, it seems to be safe and offers a more targeted, patient-specific ablation strategy beyond PVI than adjunctive empiric lines and substrate ablation in this complex group of patients.

The performance of dipole charge density mapping integrated with robotic magnetic navigation in the treatment of atrial tachycardias.

BACKGROUND: Catheter ablation (CA) has become a well-established first-line therapy for a broad spectrum of arrhythmias, including atrial tachycardias (ATs). In this study we aimed to assess the performance of the integrated novel high-resolution new generation noncontact mapping system (AcQMap) with robotic magnetic navigation (RMN) system in CA procedures for patients with ATs including comparing patient subgroups based on the utilized mapping modality, arrhythmia mechanism, localization and type of procedure. METHODS: All patients undergoing CA for AT using the AcQMap-RMN system were included. Procedural safety and efficacy were characterized by intra- and post-procedural complications. Acute procedural success and the long-term outcome were assessed in the overall group and in the subgroups. RESULTS: A total number of 70 patients were referred for CA with atrial arrhythmias including 67 AT/AFL (mean age 57.1 ± 14.4 years), and 3 additional patients with inappropriate sinus tachycardia. Thirty-eight patients had de novo AT, 24 had post-PVI AT including 2 patients with perinodal AT, and 5 had post-MAZE AT. Two patients (2.9%) suffered post-procedural complications including 1 patient with groin hematoma and 1 patient with a transient ischemic attack. Acute success was achieved in 63/67 (94.0%) procedures. Thirteen patients (19.4%) had documented recurrence at the end of the 12-months follow-up period. The performance of AcQMap was equally good in focal vs. reentry mechanisms (p = 0.61, acute success), in the left and right atrium (p = 0.21). CONCLUSIONS: AcQMap-RMN integration might improve success rates in CA of ATs with low number of complications.

Single-beat global atrial mapping facilitates the treatment of short-lived atrial tachycardias and infrequent premature atrial contractions.

BACKGROUND: Short runs of atrial tachycardias (ATs) and infrequent premature atrial contractions (PACs) are difficult to map and ablate using sequential electrophysiology mapping techniques. The AcQMap mapping system allows for highly accurate mapping of a single atrial activation. OBJECTIVES: We aimed to test the value of a novel dipole charge density-based high-resolution mapping technique (AcQMap) in the treatment of brief episodes of ATs and PACs. METHODS: Data of all patients undergoing catheter ablation (CA) using the AcQMap mapping system were reviewed. RESULTS: Thirty-one out of 219 patients (male n = 8; female n = 23) had short runs of ATs (n = 23) and PACs (n = 8). The mean procedural time was 155.3 ± 46.6 min, with a mean radiation dose of 92.0 (IQR 37.0-121.0) mGy. Total radiofrequency application duration 504.0 (271.0-906.0) s. Left atrial localization of ATs and PACs was identified in 45.1% of the cases, right atrium localization in 45.1%, and septal origins in 9.8% of the cases. Acute success was achieved in 30/31 (96.8%), and recurrence during the follow-up developed in six patients (19.4%), including four patients with PACs and two patients with short-lived ATs. One patient presented procedure-related groin hematoma as minor complication. CONCLUSION: Brief episodes of highly symptomatic ATs and infrequent PACs can be mapped using charge density mapping and successfully ablated with high acute and long-term success rates.

Left atrial anatomical variations correlate with atrial fibrillation sources near the left atrial ridge.

Introduction: Anatomical variations and characteristics of the left atrium (LA) may have a previously undescribed effect on source locations in atrial fibrillation (AF). This is the first study aiming to investigate the relationship between anatomical characteristics of the LA and non-PV sources detected by electrographic flow (EGF) mapping in patients with persistent AF. Materials and methods: We analyzed cardiac computed tomography (CT) and EGF mapping data in patients who underwent radiofrequency catheter ablation (CA). EGF mapping is a novel method based on Horn-Schunk flow estimation algorithm, used to estimate cardiac action potential flow in the atria that can detect AF sources in patients with persistent AF. By analyzing EGF maps obtained during CA procedures, we localized non-PV sources in the LA. Results: Thirty patients were included in this study (mean age 62.4 ± 6.8 years). Ten patients had AF sources near the LA ridge, while twenty patients had no leading source (source activity > 26%) near the LA ridge. LA anatomical characteristics, left atrial appendage (LAA) length, and ostial diameter showed no correlation with the presence of a leading source. We documented 19 patients with abutting LAA and left superior pulmonary vein (LSPV) (distance < 2 mm), and 11 patients with non-abutting LAA-LSPV (distance > 2 mm). Three out of 19 patients presented with a leading source near ridge in the abutting LAA-LSPV group, while 7 out of 11 patients presented with a leading source near the ridge in the non-abutting LAA-LSPV group (p = 0.01). Conclusion: Our data suggests that non-abutting LAA-LSPV is associated with the presence of AF sources near the LA ridge.

Dipole charge density mapping integrated in remote magnetic navigation: First-in-human feasibility study.

Aims: Robotic magnetic navigation (RMN) provides increased catheter precision and stability. Formerly, only the CARTO 3 mapping system was integrated with the RMN system (CARTO-RMN). Recently, a novel high-resolution non-contact mapping system (AcQMap) has been integrated with the RMN system (AcQMap-RMN) for the treatment of atrial fibrillation (AF) and atrial tachycardias (AT). We aim to compare the safety, efficiency, and efficacy of AcQMap-RMN with CARTO-RMN guided catheter ablation (CA) procedures. Material and methods: In this prospective registry, procedural safety efficiency and outcome data from total of 238 consecutive patients (147 AcQMap-RMN and 91 CARTO-RMN patients) were compared. Results: AcQMap-RMN is non-inferior in the primary endpoint of safety as compared to CARTO-RMN across the whole group (overall procedural complications in 5 (3.4%) vs. 3 (3.3%) patients, p = 1.0). Overall procedure durations were longer and associated with more fluoroscopy use with AcQMap-RMN (172.5 vs. 129.6 min, p < 0.01; 181.0 vs. 131.0 mGy, p = 0.02, respectively). Procedure duration and fluoroscopy use decreased significantly between the first 30 and the last 30 AcQMap-RMN procedures. The AcQMap-RMN system had fewer recurrences after persistent AF ablations and was non-inferior in paroxysmal AF patients compared to CARTO-RMN at 12 months (36.6% vs. 75.0%, p = 0.04, PAF 6.6% vs. 12.5%, p = 0.58; respectively). CA of AT outcomes were better using the AcQMap-RMN system (1 year recurrence 17.1% vs. 38.7%, p < 0.05). Conclusion: AcQMap-RMN integration has no negative impact on the excellent safety profile of RMN guided ablations. It improves outcomes of CA procedures for persAF and AT but requires longer procedure times and higher fluoroscopy use during the initial learning phase.

Treatment of brief episodes of highly symptomatic supraventricular and ventricular arrhythmias: a methodological review.

INTRODUCTION: Patients with brief arrhythmias are a challenging group to treat effectively with catheter ablation. Current standard approaches for the localization and treatment of brief arrhythmias suffer from several limitations, including the lack of spatiotemporal stability and adequate resolution. Recently, novel methods became available that open new perspectives and can be implemented both on the atrial and ventricular level to approach the diagnosis and treatment of these arrhythmias. AREAS COVERED: In this paper, we demonstrate in each section a novel mapping modality that has a potential to approach arrhythmias considered unmappable in the past. After describing the method, we focused on the most important features of each system that makes mapping of short arrhythmias feasible. At the end of each section, we gave a short overview about necessary developments to improve the utility of these systems in the near future. EXPERT OPINION: Treating brief episodes of tachycardias remains a challenge and can cause significant frustration for electrophysiologists. Although the broadening of the indication is clearly visible, currently available sequential mapping techniques often fail to map short-lived arrhythmias. New beneficial technological features permit the mapping of these previously considered unmappable arrhythmias, and offer a new perspective in their management.

Novel SuperMap feature of dipole charge density mapping technique offers advantages for redo catheter ablation in highly symptomatic patients with inappropriate sinus tachycardia: A case series.

Ablation procedures using classical sequential mapping systems may fail to eliminate IAST. The AcQMap dipole charge density mapping technique may offer improved accuracy and has a potential added value for the ultimate success of eliminating IAST. The use of the AcQMap should be considered for redo, as well as first line therapy for patients with symptomatic IAST.