Detection of Spatio-Temporal Dispersion Electrograms Using Complex Signal Identification-Labeled Abnormal Potential...

Ablation targeting spatio-temporal dispersion electrograms (STDEs) in addition to pulmonary vein isolation (PVI) has been reported to reduce atrial fibrillation (AF) recurrence in patients with persistent AF.

However, STDE identification remains subjective. Complex Signal Identification (CSI), integrated into the CARTO 3 mapping system, automatically quantifies electrogram characteristics. We evaluated whether CSI parameters can accurately identify STDEs.

We retrospectively analyzed intracardiac electrogram points from five consecutive patients who underwent catheter ablation for persistent AF using the CARTO 3 version 8 mapping system (Biosense Webster, Diamond Bar, CA, USA) between October and December 2024 to evaluate the ability of CSI parameters to identify STDEs. STDEs were identified and marked by the operator using an OCTARAY catheter.

A total of 4453 electrogram points obtained before ablation were analyzed. Among all CSI metrics, the fractionation score demonstrated the highest diagnostic accuracy. An optimal cutoff of 4.1 yielded an area under the curve (AUC) of 0.905 (95% CI: 0.892-0.918), with a sensitivity of 80.4%, specificity of 98.6%, positive predictive value of 94.1%, and negative predictive value of 93.1%. In contrast, complex duration (cutoff ≥ 50 ms), %cycle length (cutoff ≥ 15%), and complex onset (cutoff ≤ -32) showed AUCs of 0.613 (95% CI: 0.557-0.668), 0.599 (95% CI: 0.538-0.660), and 0.525 (95% CI: 0.461-0.589), respectively.

A CSI fractionation score cutoff of 4.1 identified STDEs with high accuracy, suggesting that CSI-guided mapping may serve as a practical tool for adjunctive ablation beyond PVI.