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Figure 1 Derivation of strain rate (SR) and strain from tissue Doppler data. A series of velocity curves (comprising isovolumic contraction [IVC], systolic [S] and diastolic [E and A] components) show a velocity gradient along a length of the wall (labeled d in the color Doppler image in A). A regression calculation between adjacent tissue velocity data points along this length generates the strain rate curve (B), which is then integrated to calculate strain (C). Timing of end-systole can be confirmed from the tissue Doppler waveform—in a separate example, the aortic valve closure (AVC) is marked by a transient wave in the adjacent septum and anterior mitral leaflet (D). ES = end-systolic; IVR = isovolumic relaxation.
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