Structural barrier increases QT-peak dispersion in swine left ventricle in vivo.

QT dispersion (QTD) is thought to represent the regional nonuniformity of ventricular repolarization and can serve as a prognostic marker for vulnerability to ventricular arrhythmias and risk for sudden cardiac death (SCD). In this study, we used an in vivo swine model to investigate the change of QT-peak dispersion before and after the introduction of a left-ventricular (LV) free-wall structural barrier (SB). Baseline and post-ablation pacing were delivered to: (i) the epicardial LV base, (ii) the epicardial LV apex, and (iii) the right ventricular (RV) endocardium.