Combined use of CT and ECGI in a canine model of ischemic dyssynchronous heart failure demonstrated significant septal to lateral wall mechanical contraction delay (80 vs 123 ms, P=0.0001).
Does combined CT and ECGI imaging characterize electromechanical function in a canine model of ischemic dyssynchronous heart failure?
Combined CT and ECGI imaging can successfully map electromechanical function and decoupling in ischemic dyssynchronous heart failure, offering a potential tool to study regional substrates in CRT candidates.
p-value: p=0.0001
INTRODUCTION: The interplay between electrical activation and mechanical contraction patterns is hypothesized to be central to reduced effectiveness of cardiac resynchronization therapy (CRT). Furthermore, complex scar substrates render CRT less effective. We used novel cardiac computed tomography (CT) and noninvasive electrocardiographic imaging (ECGI) techniques in an ischemic dyssynchronous heart failure (DHF) animal model to evaluate electrical and mechanical coupling of cardiac function, tissue viability, and venous accessibility of target pacing regions. METHODS AND RESULTS: Ischemic DHF was induced in 6 dogs using coronary occlusion, left bundle ablation and tachy RV pacing. Full body ECG was recorded during native rhythm followed by volumetric first-pass and delayed enhancement CT. Regional electrical activation were computed and overlaid with segmented venous anatomy and scar regions. Reconstructed electrical activation maps show consistency with LBBB starting on the RV and spreading in a "U-shaped" pattern to the LV. Previously reported lines of slow conduction are seen parallel to anterior or inferior interventricular grooves. Mechanical contraction showed large septal to lateral wall delay (80 ± 38 milliseconds vs. 123 ± 31 milliseconds, P = 0.0001). All animals showed electromechanical correlation except dog 5 with largest scar burden. Electromechanical decoupling was largest in basal lateral LV segments. CONCLUSION: We demonstrated a promising application of CT in combination with ECGI to gain insight into electromechanical function in ischemic dyssynchronous heart failure that can provide useful information to study regional substrate of CRT candidates.
Dawoud et al. (Wed,) conducted a other in Ischemic dyssynchronous heart failure (n=6). Cardiac computed tomography (CT) and noninvasive electrocardiographic imaging (ECGI) was evaluated on Mechanical contraction septal to lateral wall delay (p=0.0001). Combined use of CT and ECGI in a canine model of ischemic dyssynchronous heart failure demonstrated significant septal to lateral wall mechanical contraction delay (80 vs 123 ms, P=0.0001).