[Show abstract][Hide abstract] ABSTRACT: Speckle tracking echocardiography is a tool for measuring myocardial velocities from echocardiography. Since the measured velocities are noisy, only global measures are obtained. The use of wavelet de-noising for filtering the raw velocities, allows processing the high spatial frequency components, and this may reveal new insight into cardiac mechanics. Echocardiography was applied to 27 normal rats, and the myocardial velocities from 3 short axis levels were analyzed by a commercial speckle tracking program and by a wavelet de-noising process. Thereafter, the circumferential and radial strains were calculated for 6 segments. The circumferential strain was heterogeneous at the apical and basal levels (P<;0.001); while it was homogeneous at the mid-ventricular level. The radial strain was heterogeneous at all scan levels (P<;0.01). Wavelet de-noising of the myocardial velocities reveals heterogeneity of the circumferential and radial strains.