Background

Ablation of atypical atrial flutter is a challenging clinical task, supported by conventional entrainment maneuvers as well as novel high-density mapping systems. The utilization of HD mapping systems offers precise visualizations of reentrant circuits and identification of slow conductions zones and isthmus sites. The aim of this study was to analyze the impact of HD mapping and targeted ablation of slow conduction zones on outcome after atypical flutter ablation.

Methods

N=337 consecutive patients were referred for ablation of atypical atrial flutter. N=118 patients underwent high-density LA activation mapping (Rhythmia HD + Orion basket catheter, EnSite Velocity + HD Grid) and additional right-atrial activation mapping when necessary. N=219 patients underwent conventional atypical flutter ablation using standard circular mapping catheters, 3D navigation and entrainment maneuvers. Procedural and clinical data were analyzed and patients were followed-up at 3, 6 and 12 months after the procedure. The utilization of HD mapping technology was correlated with clinical outcome using a Kaplan-Meier-Analysis, baseline and procedural data were compared against each other.

Results

In a 12 months follow-up period, patients in which HD mapping technology was utilized showed a significantly better outcome. The figure shows the Kaplan-Meier-Analysis.

Patients in which HD mapping technology was used were not significantly different in baseline characteristics and procedural data (age: 67.4±12 vs. 67.1±12 years, p=0.84; procedure duration: 127±61 vs. 135±67 min, p=0.38; RF duration: 35±20 vs. 32±17 min, p=0.33).

Conclusions

Utilization of HD mapping systems facilitated a precise identification of reentrant circuits in all clinical cases and targeted ablation of flutter circuits. The patient group treated with HD mapping technology showed a significantly better outcome than the patient group treated without HD mapping technology.