Although some pioneering work had been done in the 1980s, it was not until the 1990s that cardiac strain imaging by ultrasound drew significant clinical interest in the quest for a quantitative measure of regional myocardial (contractile) function. The original methodology relied on Doppler techniques, but later on other techniques – commonly referred to as speckle tracking – entered the scene, avoiding some of the pitfalls of the original methodology. At present, cardiac strain imaging has become an established diagnostic tool in echocardiography that has been demonstrated to be more prognostic than traditional functional indices, e.g. ejection fraction. Moreover, it has now reached a level of maturity to be included in the guidelines for monitoring the progression of certain diseases and/or their treatment.
This chapter starts with a recapitulation of the nomenclature of strain in the cardiac setting. Next, a brief review is given of the different technical approaches taken towards cardiac motion and deformation estimation using ultrasound as well as the available methodologies for validating these measurements. Subsequently, a glimpse on the typical clinical workflow is given and two important clinical applications are presented. Finally, a look into potential future developments concludes this chapter.