2.3 Strain echocardiography examination
The images were acquired at the left parasternal short axis views,
apical long axis, apical four‐chamber, and apical two‐chamber views. All
off‐line analyses were performed by an investigator experienced in
speckle tracking analysis using the Q-lab workstation version
10.8.5(Phillip Medical Systems). The investigator was blinded to the
patient’s management and outcome information. The endocardium was
defined by manual tracing and the region of interest (ROI) was adjusted
to the compact myocardium thickness. Default settings for smoothing and
drift compensation were used. We evaluated longitudinal and
circumferential strain. LV longitudinal strain analysis was performed on
apical view. Circumferential strain was performed on short-axis views of
three segments; basal, mid and apex.Care was taken to ensure that the
basal short-axis at the level of mitral valve, and the apical plane
distal to the papillary muscle. The region of interest width was
adjusted first, to include the entire endocardium. From the analysis, we
received 18 regional longitudinal strain (RLS) and circumferential
strain (RCS). These allowed us to calculate the segmental longitudinal
and circumferential strain and the global longitudinal strain (GLS) and
circumferential strain (GCS) as well. Using the same software, the LA
endocardial border was traced in the apical 4-chamber view and apical
2-chamber view, care was taken to exclude the appendage and pulmonary
veins from the LA cavity. Then, a composite LA longitudinal strain
(LAGLS) curve throughout the cardiac cycle was generated. The frame rate
of 58 ±3 frames/sec was obtained for the LV and LA strain analysis.