2D- Speckle Tracking Strain Data
STE was conducted according to the recommendations of the American
Society of Echocardiography and the European Association of
Cardiovascular Imaging 16. Apical 4-, 3-, 2- chamber
views for longitudinal deformation parameters of LV and parasternal
short axis (PSAX) views from base to apex for circumferential
deformation parameters of LV were obtained and stored for offline
analysis in three consecutive cycles. Strain measurement was assessed
offline from obtained 2D echocardiographic images using dedicated
software with frame rates of ≥ 60 frame per second. Firstly, apical 3-
chamber (A3C) was selected to determine aortic valve closure time.
Endocardial and epicardial border were tracked automatically for A3C,
and then automatic tracking of endocardial and epicardial borders were
checked carefully. Furthermore, endocardial-epicardial tracking and
analysis were performed for both apical 4- chamber (A4C) and apical 2-
chamber (A2C). 2D-peak longitudinal systolic strain, peak longitudinal
systolic strain rate (SRS), longitudinal early diastolic
strain rate (SRE) and longitudinal late diastolic strain
rate (SRA) were analyzed for the 17 segments from all of
the apical views. The result of analysis was shown as either bullseye
map (Figure 1A) and longitudinal strain, strain rate (SR) curves (Figure
1B, 1C). For circumferential strain analysis, apical, mid and basal PSAX
views were selected. Endocardial and epicardial border were traced
automatically for each segments and then contour tracing was checked and
confirmed. The software calculated automatically circumferential
systolic strain, circumferential peak SRS,
circumferential SRE and circumferential
SRA for each 16 segments from entire transmural LV of
PSAX views. Like longitudinal strain analysis, the results of
circumferential strain analysis was presented in a bullseye map or
strain /SR curves.