Normalization of heterogeneity estimate. The RD, relative dispersion of regional flows, is the standard deviation of the regional flows in regions of size m in grams divided by the mean flow for all the regions together, in this case the whole left ventricle, LV. The LV mass was 50 g. The dashed vertical line at 0.5 g, 1% of LV mass, intercepts the observed fractal relationship at RD = 0.262. The regression equation is RD(m) = 0.232 (m/m0)−0.18 using m0 = 1 g. The fractal dimension D = 1.18. (Data are from 11 sheep. See (12)).