Strain and strain rate imaging: a new clinical approach to quantifying regional myocardial function.

On the basis of color Doppler myocardial motion data, 1-dimensional regional natural strain rate and strain curves can now be calculated by comparing local myocardial velocity profiles. Such deformation data sets may be an important, new, and more sensitive approach to quantifying both regional radial and long-axis function of the left or right ventricle in both acquired and congenital heart disease. The normal ranges of regional velocity, strain rate, and strain values have already been determined in both adults and children. This review will focus both on the potential clinical applications of these new ultrasound-based deformation parameters and the current limitations inherent in implementing the technique in everyday practice.