Electrogram Frequency Analysis and Isochronal Activation Surface Area Mapping for Ablation of Premature Ventricular Contractions.

Introduction A lower frequency early electrogram (EGM) or broad area of early activation during premature ventricular contraction (PVC) mapping may be associated with a PVC origin in an opposing chamber or deep within the mapped surface. The utility of quantifying EGM frequency at early activation sites and isochronal activated surface area (IASA) is unclear. Our study aimed to investigate the utility of EGM frequency analysis and IASA mapping to complement activation mapping during PVC ablation. Methods High density PVC activation and IASA maps were created using a multi‐electrode mapping catheter in 25 patients undergoing PVC ablation. EGMs in early activation regions were retrospectively studied. IASAs in each mapped chamber were analyzed. Results Ablation success was achieved in 18 of 25 (72%) patients. Ablation was successful in all patients with EGM frequency > 325 Hz (local activation time (LAT) range 28–54 ms) and in all patients with pre‐QRS LAT > 40 ms (EGM frequency range 127–563 Hz). In patients with pre‐QRS LAT < 40 ms and EGM frequency < 325 Hz, ablation was successful in 9 of 16 cases (56%). Mean IASA mapped within 10 ms was smaller at successful ablation sites compared to opposing chambers (0.33 vs 0.95 cm 2 , p = 0.02). All ablation in chambers with IASA > 1.5 cm 2 within 10 ms was unsuccessful. Conclusion Higher EGM frequency and smaller IASA were associated with successful ablation of PVCs. Ablation at sites with EGM frequency > 325 Hz was successful in all patients. The utility of identifying higher frequency EGMs at early activation sites requires further study.