Long or Short Post-Pacing Interval Response to VT Entrainment: What Is the Mechanism?

A 58 year old male with nonischemic cardiomyopathy and ejection fraction of 25% presented with VT storm. Epicardial mapping revealed an inferolateral scar and during tolerated VT with right bundle branch superior axis morphology with V3 transition (tachycardia cycle length [TCL] 325 ms), overdrive pacing was performed. What is the response to entrainment and why? (FIGURE 1A)
Source: Heart Rhythm - Category: Cardiology Authors: Source Type: research