Ultra High-Density Mapping and Ablation of Localized Micro-Reentrant Tachycardias: Insight From the CHARISMA Registry

Area of Science:

• Electrophysiology
• Cardiovascular Medicine

Background:

• Ultra-high-density mapping (UHDM) with automated features improves understanding of micro-reentrant atrial tachycardias (mAT) circuits.
• Precise localization of mAT origins is crucial for effective ablation strategies.

Purpose of the Study:

• To assess the diagnostic utility of an automated UHDM algorithm in guiding catheter ablation of mATs.
• Evaluate the effectiveness of this technology in real-world clinical practice.

Main Methods:

• Prospective enrollment of patients undergoing AT ablation across 22 Italian centers.
• Comprehensive atrial mapping using the RHYTHMIA system and LUMIPOINT tool for electrogram fragmentation confirmation.
• Analysis of 159 atrial tachycardias (ATs), categorizing them into macro-reentrant, focal, and mAT types.

Main Results:

• Out of 159 ATs, 12 (7.5%) were identified as mATs.
• mAT origins were localized to various atrial regions, with low voltage areas (<0.1 mV) consistently found at the origin site.
• A low recurrence rate of 3.1% for AT/AF was observed post-ablation, with 8.3% recurrence specifically in the mAT group.

Conclusions:

• A novel automated algorithm and ORION catheter facilitate accurate mAT description and ablation.
• Transcatheter ablation targeting the localized origin of mATs demonstrates a satisfactory procedural success rate.
• This approach offers a promising solution for managing this rare form of atrial tachycardia.