Two-dimensional (2D) Speckle tracking strain curve:
Myocardial deformation imaging by two-dimensional (2D) strain based on speckle tracking deformation imaging, as an index of contractile function, was assessed on grey-scale echocardiographic images. (17) Electrocardiogram was contacted to the patient’s chest till proper adjustment of the heart rate recording on the echocardiography machine. A frame rate of 80-100 frames/sec was utilized for storage and analysis. At least three consecutive cardiac cycles of 2D apical four-chamber images were documented at each plane and were introduced into the GE Echo-PAC (BT 09, Horten, Norway) workstation to select the best Speckle tracking analysis images. The images were optimized to visualize the myocardial walls. 2D speckle tracking offline analysis software was automatically tracked the endocardial, epicardial borders and the myocardial movement of the RV frame by frame, thus delineating a region of interest composed of six segments including (Basal-lateral, mid-lateral, apico-lateral, apico-septal, mid-septal and basal-septal). The analysis was established when adequate tracking was confirmed by visual inspection and the software. If the tracking of the RV endocardium was unsatisfactory, manual adjustments of the region of interest size were achieved to confirm optimal tracking. RV systolic strain curves were assessed in the longitudinal direction for each segment by the software. Once approved, the software displayed an average which is the global longitudinal strain (GLS) to assess the global RV myocardial function automatically. (18-20) These echocardiographic measures were recorded and reported at rest and after dobutamine stress.