Mapping Efficiency of an Octaspline Versus Pentaspline Multielectrode Catheter for High-Density Mapping of Regular Atrial Tachyarrhythmias: A Multicenter Randomized Cross-Over Trial

Background: Catheter ablation of regular atrial tachyarrhythmias (ATs) relies on high-density electroanatomical mapping and can be technically challenging. We compared the mapping efficiency of the Octaray and Pentaray catheters in patients undergoing AT mapping. Methods: Patients with either left or right AT underwent three-dimensional Coherent mapping using both the Octaray and Pentaray catheters in a randomized cross-over design. The primary endpoint was the total number of electrograms acquired per map at a predefined filling threshold of 5 mm. Results: A total of 46 patients with left or right AT were enrolled across three ablation centers. Successful mapping with both catheters was achieved in 39 patients (20 left ATs and 19 right ATs). The median number of electrograms acquired per map (7437 vs. 4679; p < 0.001) and median electrogram density (50.2 vs. 29.8 electrograms/cm2; p < 0.001) was significantly higher with Octaray than with Pentaray. Furthermore, median mapping times were significantly shorter with Octaray (5.4 vs. 8.1 min; p < 0.001), resulting in an approximately 2.5-fold higher acquisition rate (1489 vs. 602 electrograms/minute; p < 0.001). In addition, Octaray demonstrated a significantly lower proportion of internal points compared with Pentaray, particularly in low-voltage regions (bipolar voltage < 0.5 mV; 22% vs. 44%; p = 0.01). Conclusions: Compared with Pentaray, use of the Octaray catheter facilitated faster high-density electroanatomical mapping of complex ATs, thereby improving mapping efficiency.