Characteristics and outcomes of pace mapping for ablation of premature ventricular complexes

Background/Introduction Activation mapping is the “gold standard” for localisation of the site of origin during mapping and ablation of symptomatic premature ventricular complexes (PVC). In case of suppression of PVCs during the procedure, the origin of the PVC can be located using a pace mapping technique. The PASO module is an addition in the CARTO3 mapping system that calculates the correlation between the induced and observed 12-lead ECG PVC morphology, and visualises this correlation on an isochronal 3D colour map. Purpose The aim of this study was to compare the follow-up success rate of pace mapping using the PASO module and activation mapping and to determine cut-off values for clinical success. Methods Seventy-six consecutive ablation procedures of symptomatic PVCs were included in this single-center retrospective study. Mapping and ablation parameters were derived from the CARTO3 mapping system. Ablation success was defined as a ≥95% reduction in PVC burden on 24-hour Holter recordings or absence of the clinical PVC on multiple ECGs in case of multiple PVC morphologies. Logistic regression analysis was performed to evaluate the relationship between applied mapping methods and ablation parameters. Optimal cut-off values of ablation characteristics for successful ablation were determined using ROC curves. Results Thirty-five (46%) patients were male and 39 (51%) patients had a reduced left ventricular ejection fraction. Pace mapping was used in 36 (47%) patients. Baseline PVC burden was lower in patients when pace mapping was applied (18% vs. 28%, p<0.001). The use of either mapping technique was influenced by PVC localisation (p=0.004). Pace mapping was used predominantly in the right ventricular outflow tract (n=21/31) whereas activation mapping was used predominantly in the left ventricle (n=14/22) and left ventricular outflow tract (n=7/7). Ablation success did not differ between activation mapping (77.5%) and pace mapping (77.8%). Median [IQR] maximum PASO correlation was 98.2% [97.1–98.6] for successful ablations and 96.5% [92.9–97.5] for unsuccessful ablations (p=0.030). The optimal cut-off value for successful ablation of the PASO correlation was 97.6% (AUC 0.754, sensitivity 68%, specificity 88%). There were no significant differences in other ablation parameters between both groups. Conclusion This study indicates that pace mapping using PASO is a good alternative for activation mapping for localisation of the PVC. A minimum PASO correlation coefficient of 97.6% is the optimal cut-off value for successful PVC ablation. ROC of maximum PASO coefficient Funding Acknowledgement Type of funding source: None