Abstract #3613

Zhong J, Jeyaraj D, Flask C, Wilson L, Rosenbaum D, Yu X

Pacing induced ventricular electrical remodeling (VER) may lead to heart failure and increased cardiac mortality. To investigate the mechanisms for VER, MRI tagging was performed on 5 mongrel dogs with pacing leads implanted in right atrium and on the surface of anterior and posterior LV wall. Segmented circumferential and radial strains were measured. Similar strains were found between ventricular segments during atrial pacing. However, pacing from LV wall preferentially increased strains in the late-activated segments. The increased strains were associated with prolongation of action potential duration. Our results indicate that altered strain patterns may represent a potential mechanism for VER.