Speckle-tracking echocardiography
The RALS was measured using STE, a relatively newer echocardiographic
method for obtaining strain and strain rate measurements. For STE using
2D grey-scale echocardiography, apical four-chamber views were captured
during breath holding at the end of expiratory phase for few seconds,
and with electrocardiogram recording attached. A suitable image of
myocardial tissue was obtained completely separated from surrounding
structures. Three successive cardiac cycles were recorded and averaged.
The frame rate was set between 60 and 80 frames per second. Analysis of
speckle-based strain was done using Philips QLAB version 9.0 software.
In four chamber RA focused views, the endocardial surface of the RA was
traced manually by a three-point and-click approach. The system
automatically generates an epicardial surface tracing. The region of
interest (ROI) was therefore created, composed of 7 segments. The ROI
was manually adjusted as needed to allow for enough speckle tracking.
The software generates the longitudinal curves for each segment with its
mean value. (20–22)(Figure 2)