Normal Range of Left Ventricular 2-Dimensional Strain

Abstract

Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp wo-dimensional (2-D) speckle tracking echocardiography (STE) is being increasingly used for the quantification of global and regional left ventricular (LV) mechanics. 1,2 Previous studies have validated the accuracy of STE against cardiac magnetic resonance imaging, a reference standard. 3, 4 The superiority of STE compared with LV ejection fraction has been reported in several clinical settings. 5-7 The rapid advancement of computer technology allows us to measure layer-specific strain across the myocardium using some ultrasound systems and software. 8-10Despite the rapid adoption of this new technology, the normal range of LV 2-D strain has been traditionally measured in a small number of subjects. Little information exists regarding the equivalency of the normal ranges of LV 2-D strains when comparing ultrasound systems from different vendors; moreover, evidence for a good inter-vendor agreement of 2-D strain data from the same subjects remains to be elucidated. 11-14 This inter-vendor agreement of 2-D strain is necessary for conducting a longitudinal follow-up or a cross-sectional assessment of the LV function using 2-D strain, because many ultrasound laboratories utilize a variety of ultrasound systems and analysis software packages from different vendors. Accordingly, in this multicenter study of healthy volunteers, the aims were to (1) establish the normal range of LV 2-D strain in a large number of healthy subjects; and (2) determine the inter-vendor, observer and test-retest variabilities of 2-D strain. Satoshi Nakatani, MD on behalf of the JUSTICE investigatorsBackground: To determine the normal range of left ventricular (LV) 2- dimensional (2-D) strain and vendor-specific differences, a multicenter prospective 2-D strain study endorsed by the Japanese Society of Echocardiography was conducted.

Intervendor Variability of Two-Dimensional Strain Using Vendor-Specific and Vendor-Independent Software

“…Among 193 subjects who were enrolled to determine intervendor variability in the Japanese Ultrasound Speckle Tracking of the Left Ventricle study, 10 we selected 81 subjects aged $20 years (GE vs Philips in 26 subjects, Philips vs Toshiba in 31 subjects, and GE vs Toshiba in 24 subjects). The subjects were enrolled from four hospitals in Japan and were primarily hospital employees, their relatives, and other volunteers recruited via advertising.…”

“…Recent studies have demonstrated that intervendor peak strain values measured by vendor-specific software in the same subjects are frequently different and incomparable. [7][8][9][10] In clinical situations, the majority of ultrasound laboratories use several ultrasound machines from different vendors for routine echocardiographic examinations. Therefore, any longitudinal studies evaluating changes in strain values using 2D speckle-tracking software should consider the reliability of results obtained using different vendor-specific software algorithms.…”

Discrepancy between regional left ventricular regional circumferential strain assessed by MR-tagging and by speckle tracking echocardiography

“…These results, are not influenced by the base-apex positioning and by the type of machine used [3] . Diagrams of the figure 5 summarize those contradictory MR and STE published results.…”

“…If we consider regional Ecc analysis, largely investigated through single modality studies (STE or MR-tagging performed separately), highest lateral absolute Ecc is constantly reported in MR-based literature [5,[16][17][18][19][20][21] and highest septal absolute Ecc is constantly reported in the STE based literature [3,4,10,11,22,23] . These results, are not influenced by the base-apex positioning and by the type of machine used [3] .…”

“…Normal values of regional Ecc, which determine the threshold for detection of segmental contraction abnormalities, appear to be quite variable in the literature (e.g. higher septal Ecc values by STE [3,4] and lower septal Ecc values by MR-tagging [5] as compared with lateral Ecc values). However, no direct comparative study of regional circumferential strain has been published yet between MR-tagging and STE.…”