Catheter Ablation -> Ventricular Arrhythmias -> Mapping & Imaging D-PO01 - Featured Poster Session (ID 11) Poster

D-PO01-186 - Left Ventricular Substrate Characterization By Conduction Velocity In Sinus Rhythm, Ventricular Pacing, And Ventricular Fibrillation (ID 957)


Background: Ventricular tachyarrhythmias after myocardial infarction remain a common cause of sudden death. Scar or replacement fibrosis is known to be an underlying substrate for these fatal rhythms. Substrate mapping during sinus rhythm is a low-risk approach to identifying ablation targets for these arrythmias.
Objective: To explore whether shared areas of consistent conduction slowing or block could be identified irrespective of wavefront direction and rate (during sinus rhythm, ventricular pacing from multiple sites, and ventricular fibrillation [VF]).
Methods: Anterior infarcts were induced in 3 sheep via intracoronary ethanol infusions. Conduction velocities (CV) were computed from charge density using a polynomial fitting method during sinus rhythm and during pacing from 3-5 sites as well as during 4-5 seconds of VF (AcQMap, Acutus Medical). Regions of consistently slow CV were compared to areas of scar as identified on enhanced cardiac MRI.
Results: Localized areas of consistently slow CV were observed in all animals during all rhythms, including VF (mean 24 wavefronts). These areas most often corresponded to border regions of ventricular scar identified on MRI (Figure).
Conclusion: Our study suggests that localized regions of the ventricle with consistently slow CV exist, including during VF, and that they are often found near scar borders. These regions could be identified through interrogative substrate mapping during ventricular pacing from varied sites.