The larger the PSD, the more different the OMC of myocardial regions are, the more uneven the distribution of OMCs is, the more severe the degree of dyssynchrony. Normally, when the heart muscle regions have synchronized contractions, the OMC of 5 600 myocardial regions will be close to each other, creating a chart with a high shape, narrow legs, a normal distribution with a deviation index (Skewness index) close to 0 and the oblique index (Kurtosis index) is close to 3.