Abstract 3039: Accuracy of a 2D Speckle Tracking Method for Defining Cardiac Twist
Background: Opposite directions of left ventricular (LV) twist at basal and apical levels produce a wringing torsional motion which assists LV ejection in systole and unwind to augment ventricular filling early in diastole. Tracking the degree of twist could provide important clinical information in normal and diseased hearts. During twist the angle of incidence is changing constantly, thus limiting the efficacy of angle dependent tissue Doppler based methods. We tested the accuracy of a new angle independent motion detecting method, based on speckle tracking within 2D grey scale images.
Methods: We used a variable speed motor to rotate a round wheel immersed in a water bath, by an attached hinged lever. A fresh pig heart was dissected to remove atrial and RV walls from LV which was then mounted on the wheel and rotated at 5 different speeds (30 – 80 cycles/min) at 3 different angles (15°,30°,45°). Short axis 2D and tissue Doppler images were acquired using a GE/VingMed Vivid 7 at 3.5 MHz and >100frames/sec. Data was analyzed offline by a new 2D speckle tracking based (2DSR) program embedded in EchoPac©.
Results: The 2DSR program tracked the direction and degree of torsion well with a slight persistent overestimation (mean at 15° = 16.62° ± 2.95°; mean at 30° = 34.16° ± 1.94°; mean at 45° = 49.4° ± 2.2°).
Conclusions: Results of this study using pig heart are consistent with our earlier validation model studies using fresh beef strips. This speckle tracking method can reliably track the degree of twist.