Abstract 21142: Electromechanical Wave Imaging for Noninvasive Mapping of the 3D Electrical Activation Sequence in vivo.
Cardiac conduction abnormalities constitute a major cause of death and disability worldwide. However, as of today, no noninvasive imaging technology can directly map the electrical activation sequence of the heart in the clinic. EWI is a novel ultrasound-based imaging Methods that can map the transient mechanics of the heart in a full cardiac view at a temporal resolution seven times higher than conventional ultrasound imaging. At such a resolution, the propagating deformations Resultsing from sequential, electrical activation of the myocardium, i.e., the Electromechanical Wave (EW), become detectable and are highly correlated with the electrical activation. In this study, we present and validate in vivo Electromechanical Wave Imaging (EWI) as a tool to map the transmural electromechanical and electrical activation sequence of the myocardium noninvasively. For the purpose of this validation study, electrodes were first implanted in open-chest canines. EWI was performed during sinus rhythm and four pacing schemes using a commercial ultrasound scanner (Sonix RP, Ultrasonix, Burnaby, Canada), operating at up to 520 frames/s using a customized acquisition sequence. Multiple echocardiographic views were combined to obtain a three-dimensional depiction of the EW. In all four pacing cases, the EW isochrones, i.e., maps showing the time of the electromechanical activation, identified a sole region of early activation, which precisely coincided with the location of the pacing leads. During sinus rhythm, the EW isochrones depicted complex activation patterns, with multiple early activated regions, in accordance with results available in the literature. Both during pacing and sinus rhythm, a monotonic relationship between the electrical activation times and the EW was found, hereby confirming that EWI can accurately map the activation sequence. EWI could constitute a unique, highly translational and complementary imaging tool that can map the 3D electromechanical and electrical activation of the myocardium and identify the pacing lead locations, in real-time and noninvasively.
- © 2010 by American Heart Association, Inc.