STE is a relatively new technique to achieve myocardial mechanical deformation (strain and strain rate). STE overcomes major drawbacks of conventional techniques (i.e., TDI) such as inter/intra-observer variability, angle dependence or noise interference [
64]. It uses sequence of images obtained from 2D- or 3D-echocardiography and quantifies the distance between pixels during the cardiac cycle. Thus, alterations in myocardial deformation in the three axes (radial, circumferential, and longitudinal strain) are detected. In this sense, strain and the strain rate are solid indexes for left ventricular contractility, and more independent of pre/after-load than EF [
65]. 3D-STE successfully confirmed the correlation between diabetic microangiopathy and myocardial deformation in asymptomatic T2DM patients by reduction of global longitudinal and circumferential strains [
66]. In this regard, 24% diabetic patients were diagnosed with impaired systolic function by 2D-STE, but not by other conventional strategy [
67]. Importantly, a decreased longitudinal systolic strain detected by STE was associated with cardiovascular events and provided incremental prognostic value up to ten years after revealing [
68‐
70]. Also, longitudinal strain and subsequent increased torsional deformation have been crucial to diagnose early myocardial disease in T1DM patients [
71]. In asymptomatic T1DM, 2D-STE also demonstrated subclinical left ventricular dysfunction and right systolic dysfunction [
72]. In pediatric T1DM, 2D-STE showed impaired longitudinal and circumferential strain as signs of hyperdynamic left ventricular contractility early in the course of the disease [
73]. In addition, 2D/3D-STE have been found to be highly reliable in animals [
74]. In sheep, 2D-STE provided earlier information about left ventricular function. Specifically, left ventricle free wall was affected in both short and long-axis, whereas the strain and the strain rate were altered in the radial axis [
75]. In early stage T2DM rats, 2D-STE detected left ventricular deformation associated with cardiomyocyte Ca
2+ transients delay [
76]. In T1DM rabbits, longitudinal and circumferencial strain gradually diminished from endocardium to epicardium, which was consistent with invasive labelling studies [
77]. Recently, in T1DM mice, 2D-STE showed early alterations such as systolic radial strain, radial strain rate, radial displacement, and radial velocity, as well as decreased circumferential and longitudinal strain rate during the progression of disease and earlier than contractile changes detected by 2D-Echo [
78]. However, as a weakness, irregular ventricular remodeling and wall thinning may affect STE accuracies.