Strain occurs in three primary directions in the left ventricle. (A) Strain occurs in three primary directions, and is quantified as the percent change in length in the radial, circumferential and longitudinal directions relative to the end-diastolic (most relaxed) length. (B) Example strain curves from a control mouse are shown for the 16 standardized segments of the left ventricle, color-coded according to the bullseye in (C). The peak strains occur as each segment reaches a minimum (i.e., at the point of maximum shortening). (C) Standard bullseye segmentation for the left ventricle includes dividing the ventricle into 3 slices: a basal slice further divided into 6 segments, a mid-ventricular slice further divided into 6 segments and an apical slice divided into 4 segments.