Using the QRS-VHis Interval-based Algorithm to Optimize the Ablation Process of Outflow Tract Premature Ventricular Complexes.

Background: The choice between left- and right-sided ablation for outflow tract premature ventricular complexes (OT-PVCs) during procedures remains a topic of ongoing discussion. In this study we aim to elucidate the value of the QRS-V_His interval in distinguishing between left and right origins in left bundle branch block (LBBB)-type OT-PVCs, thereby optimizing the ablation process.

Methods: The QRS-V_His interval was measured in consecutive patients with LBBB-type OT-PVCs. The performance of this interval was compared with traditional electrocardiographic (ECG) algorithms and prospectively validated in a cohort from 8 centers. Based on the interval, we developed an algorithm to assess its efficacy in optimizing the ablation process.

Results: A total of 166 patients were enrolled in the development cohort, and 53 patients in the validation cohort. The QRS-V_His interval demonstrated greater accuracy than ECG algorithms among 153 patients with typical endocardial origins (area under the curve = 0.962). At a cutoff of 30 ms, the QRS-V_His interval showed a sensitivity of 71.8% and a specificity of 98.2% for identifying left-sided locations. A flowchart was developed based on the QRS-V_His interval, indicating that a QRS-V_His value of < 30 ms necessitated left-sided ablation with a 94% likelihood, leading to an 88% success rate. Conversely, when the QRS-V_His value was ≥ 30 ms, the likelihood of requiring left-sided ablation dropped to only 16%. The accuracy of the flowchart was validated in the independent cohort.

Conclusions: The QRS-V_His interval is superior for distinguishing between left and right ventricular outflow tract origins in LBBB-type OT-PVCs and has proven valuable in optimizing the intraprocedural process.