Schematic representation of clustered (A) and disperse (B) dyssynchrony. Depending how dyssynchrony is being indexed, Results could be the same for both situations, despite markedly different impact on dsyynchrony. In example B, there is a "net" synchronous contraction. Uniformity of Strain (US) and Regional Variance of Strain (RVV) are vector derived indices differentiating clustered from dispersed dyssynchrony. Adapted from: Lardo, A. C. et al. J Am Coll Cardiol 2005;46:2223-2228.