Abstract 16918: Activation Mapping of Idiopathic Ventricular Ectopy- Characterization of a Threshold Value Predicting Successful Catheter Ablation

Background: Catheter ablation of ventricular ectopy is performed with increasing frequency. Activation mapping to locate the earliest presystolic electrogram (EGM) is the most accurate method to identify the optimal ablation site. Despite this, activation mapping of ventricular ectopy has not been systematically reviewed in a large series, and the optimal activation time predicting successful ablation has not previously been determined. The goal of this study is to determine the local presystolic activation time most predictive of successful ablation. Methods and Results: We retrospectively reviewed 100 consecutive successful endocardial PVC ablations for idiopathic ventricular ectopy and analyzed the local activation time at each successful and unsuccessful ablation site. A total of 560 ablation lesions were reviewed. Activation time was calculated as the difference between the earliest peak of the local bipolar EGM and onset of the reference surface QRS complex. Acute success was defined as complete elimination of the target PVC during the procedure with no recurrence at 30 days by ECG and follow-up Holter. A local activation time 30 ms presystolic best predicted success with a sensitivity of 80%, specificity 80%, and an area under the ROC curve of 0.906 (p 45 ms presystolic was 100% specific for successful ablation. Conclusion: In our experience, a local presystolic activation time of 30 ms is the threshold value most predictive of successful PVC ablation. Our review is the first to systematically characterize an activation time predicting success with idiopathic PVC ablation in a large cohort.