Measurement of Left Ventricular Indices
In terms of the methodology for echocardiographic imaging, the majority
of studies followed recommendations from the American Society of
Echocardiography (11), with two
studies following recommendations from the European Association of
Cardiovascular Imaging (12), for
two-dimensional echocardiographic measurements including LVEDD and LVEF.
LV-GLS was measured using software from different vendors including
TomTec Imaging systems, GE Echopac workstation, X-Strain and Syngo
Vector Imaging which increased the variability of absolute strain
values. All studies had reported mean LV-GLS values derived from offline
measurements made in the standard three apical views by at least two
operators. Despite different software used, all algorithms for strain
assessment appeared to utilise similar approaches where the endocardial
borders were manually traced throughout the cardiac cycle. Longitudinal
strain was assessed in all 17 longitudinal LV segments, and the
segmental values were averaged to give the mean LV-GLS.