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

Abstract

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.

Strain‐encoded (SENC) magnetic resonance imaging to evaluate regional heterogeneity of myocardial strain in healthy volunteers: Comparison with conventional tagging

“…The anterior apical and anterior midventricular regions showed the highest circumferential peak strain values. The lowest circumferential peak strain values obtained with SENC were seen at the inferior apical and midventricular regions, which is in line with others who have measured myocardial strain using either MR tagging or echocardiographic strain imaging (15,16,23). However, there are groups who observed, contrary to our findings, that the highest strain values can be obtained by MR tagging in the posterior region of the LV (2,22).…”

“…Comparing our strain values obtained by SENC to strain values generated with other imaging modalities in previous published studies, such as echocardiographic speckle tracking and tissue Doppler (15,20,21), we found similar strain values; however, the peak SENC values in our study were slightly higher than the peak MR tagging values in our and previous published studies (16,22,23). This phenomenon can be attributed to the higher temporal resolution of SENC resulting in a higher probability of acquisition of the peak systolic contraction.…”

“…We also could not see any gender-related changes in peak systolic strain values. Hurlburt et al (15) found a marginal, albeit statistically significant, difference in peak systolic strain values between men and women. This difference could be attributed to the use of different strain-measuring techniques.…”

“…Longitudinal strain was also slightly heterogeneous, with the highest longitudinal peak strain values at the inferior and inferolateral basal regions. Interestingly, using echocardiographic 2D strain, no regional differences in peak systolic longitudinal strain have been observed (15).…”

“…We implemented SENC for the first time in a large population of healthy volunteers. In contrast to other studies of healthy volunteers (15,16), our inclusion criteria were based not only on their clinical history and examination, but also on extensive biochemical characterizations and MR stress tests.…”