Real time strain imaging is provided by acquiring a sequence of cardiac image frames and estimating tissue displacement in the myocardium over a heart cycle. The displacements are used to calculate strain over the myocardium and a color map is formed of the strain values. During the next heart cycle the color map is warped to fit the myocardium in each image frame and the warped color map is displayed as a color overlay over the myocardium of each image of the new heart cycle as they are displayed in real time. A new color map is also produced over the new heart cycle for use with the following heart cycle. An ultrasound system which performs real time strain imaging is also described.