The present disclosure relates to a method for detecting and/or quantitatively assessing cardiac dyssynchrony of a subject based on at least one medical imaging scan showing at least part of the myocardium of the subject's heart, in particular mechanical cardiac dyssynchrony. The medical imaging scan may provide a plurality of values of a predefined myocardial deformation parameter of said part of the myocardium. In a preferred embodiment the method comprises the steps of 1) determining a myocardial deformation deviation between pairs of myocardial deformation parameter values selected from the myocardium of substantially opposite parts of a cardiac chamber, and 2) calculating the cardiac dyssynchrony of the subject based on said myocardial deformation deviation.