Feasibility and Acute Hemodynamic Outcomes of S3 Functional Mapping During Scar-Related Ventricular Tachycardia Ablation

Functional substrate mapping with ventricular extrastimuli can unmask hidden abnormal signals and deceleration zones (DZs) not identified during baseline pacing. The S3 protocol extends high-density whole-chamber mapping to two extrastimuli and may reduce reliance on prolonged activation mapping of sustained ventricular tachycardia (VT).1 Because S3 extrastimulation may precipitate acute hemodynamic decompensation (AHD), particularly in advanced structural heart disease under general anesthesia, we assessed the feasibility and acute hemodynamic outcomes of a full-S3 protocol.