Direct Ultrasound Measurement of Longitudinal, Circumferential, and Radial Strain Using 2‐Dimensional Strain Imaging in Normal Adults

Current noninvasive techniques used to evaluate left ventricular systolic function are limited by dependence on the angle of insonation (tissue Doppler imaging/TDI) or limited by availability (MRI tagging). We utilized 2-dimensional speckle strain (epsilon) imaging (1) to establish normal values for all three epsilon vectors; (2) to compare circumferential epsilon values with circumferential shortening (midwall fractional shortening (FS(mw)); (3) to examine the relationship between left ventricular epsilon and wall stress; and (4) to compare 2D echocardiographic characteristics by gender. Echocardiography was performed in 60 normal subjects (mean 39 +/- 15 years). Small, but significant regional heterogeneity was seen in circumferential epsilon, but not in radial or longitudinal epsilon. We found an inverse correlation between circumferential epsilon and stress (r =-0.29, p<0.05) as well as longitudinal epsilon and stress (r =-0.11, P < 0.05), though the relationships were not close. We also observed a linear relationship between mean circumferential epsilon and FS(mw) (r = 0.29, P < 0.05). In conclusion, (1) 2-dimensional epsilon imaging permits measurement of regional systolic epsilon values in the majority of normal individuals; (2) epsilon values furnished by this method obey expected stress-shortening relationships; (3) systolic epsilon displays minor regional heterogeneity in the circumferential direction; (4) for the first time, a close relationship between FS(mw) and mean circumferential epsilon was demonstrated; and (5) there are minor gender-related differences in LV geometry and function.