An image of a depolarization map. On the horizontal axis is the activation time, on the vertical axis is depolarization distribution in V1-V8 leads. Red color corresponds to a maximal number of simultaneously activated myocardial cells.
VDI monitor provides a set of numerical parameters that measure the electrical interventricular dyssynchrony (e-DYS) and the local depolarization duration (Vd). Vd parameters measure the speed of depolarization propagation in a single ventricular segment (lead).
Demonstration of the clinical benefit of the new parameters. It introduces relative changes of electrical dyssynchrony (e-DYS), depolarization propagation duration (Vd), and QRS duration during biventricular (BiV) and nonselective His bundle pacing. Both BiV and His pacing decrease electrical dyssynchrony (His more). In addition, Vd parameter indicates, that His bundle pacing accelerates the spread of depolarization – fast conduction, while myocardial BiV pacing slow down depolarization spreading. QRSd changes are minor and non-significant.
