Identification of Human Ventricular Tachycardia Demarcated by Fixed Lines of Conduction Block in a 3-Dimensional Hyperboloid Circuit.

Background: The circuit boundaries for reentrant ventricular tachycardia (VT) have been historically conceptualized within a 2-dimensional (2D) construct, with their fixed or functional nature unresolved. This study aimed to examine the correlation between localized lines of conduction block (LOB) evident during baseline rhythm with lateral isthmus boundaries that 3-dimensionally constrain the VT isthmus as a hyperboloid structure.

Methods: A total of 175 VT activation maps were correlated with isochronal late activation maps during baseline rhythm in 106 patients who underwent catheter ablation for scar-related VT from 3 centers (42% nonischemic cardiomyopathy).

Periaortic ventricular tachycardia in structural heart disease: Evidence of localized reentrant mechanisms.

Background: The mechanisms for scar-related ventricular tachycardia (VT) originating from the periaortic region remain incompletely characterized.

Objective: The purpose of this study was to map the circuits responsible for periaortic VT in high resolution.

Methods: Cases with periaortic VT (2016-2020) were analyzed to characterize the substrate and mechanisms with multielectrode mapping.

Simultaneous Endocardial and Epicardial Delineation of 3D Reentrant Ventricular Tachycardia.

Background: Mechanisms of scar-related ventricular tachycardia (VT) are largely based on computational and animal models that portray a 2-dimensional view.

Objectives: The authors sought to delineate the human VT circuit with a 3-dimensional perspective from recordings obtained by simultaneous endocardial and epicardial mapping.

Methods: High-resolution mapping was performed during 97 procedures in 89 patients with structural heart disease.

Targeted Ablation of Ventricular Tachycardia Guided by Wavefront Discontinuities During Sinus Rhythm: A New Functional Substrate Mapping Strategy.

Background: Accurate and expedited identification of scar regions most prone to reentry is needed to guide ventricular tachycardia (VT) ablation. We aimed to prospectively assess outcomes of VT ablation guided primarily by the targeting of deceleration zones (DZ) identified by propagational analysis of ventricular activation during sinus rhythm.

Methods: Patients with scar-related VT were prospectively enrolled in the University of Chicago VT Ablation Registry between 2016 and 2018.

Feasibility and utility of intraoperative epicardial scar characterization during left ventricular assist device implantation.

Introduction: Ventricular arrhythmias (VA) after left ventricular assist device (LVAD) placement are associated with increased morbidity and mortality. We sought to assess epicardial voltage characteristics at the time of LVAD implantation and investigate relationships between scar burden and postimplant VA.

Methods And Results: Consecutive patients underwent open chest epicardial electroanatomic mapping immediately before LVAD implantation.

Automated isochronal late activation mapping to identify deceleration zones: Rationale and methodology of a practical electroanatomic mapping approach for ventricular tachycardia ablation.

Sinus rhythm surrogates for critical isthmus sites are highly desirable because the vast majority of VT is hemodynamically unstable. While many ablation strategies to decrease the arrhythmogenicity of scar have been shown to be effective, the predominant method for electroanatomic mapping relies on a voltage-based depiction of scar and abnormal electrograms. A functional prioritization of slow conduction, distinct from late activation, is feasible in clinical practice with the creation of isochronal late activation maps.