Estimating the Myocardium's Angle of Three-Dimensional Trajectory, Using the Tracking of Sequential Two-Dimensional Echocardiography Images

BACKGROUND: In this study, the angle of the myocardium's trajectory in three dimensions (small ef, Cyrillic) was estimated by simultaneous use of long-axis and short-axis views of left ventricle septum two-dimensional images. Then correlation of three-dimensional trajectory's angle with the rotation angle from the long (chi) and short (theta) axis views was estimated and compared at the three levels of base, mid and apex of the interventricular septum wall. METHODS: Two-dimensional echocardiography images of long- and short-axis views of 19 healthy men were recorded and analyzed. Using an electrocardiogram of each individual, the images of the two views were synchronized. The interventricular septum wall motion at the three levels of base, mid and apex were estimated, using a block matching algorithm throughout three cardiac cycles. Considering the defined system of coordinates and the position vectors in long and short-axis views, the 3-dimensional angle of the trajectory was calculated. RESULTS: Maxima of the small ef, Cyrillic, theta, and chi angles were extracted at 16.33 +/- 3.01, 10.61 +/- 3.38, and 15.11 +/- 3.30 degrees at base level, 22.77 +/- 4.95, 7.78 +/- 2.96, and 16.72 +/- 2.66 degrees at mid level and 14.60 +/- 5.81, 10.37 +/- 5.48, and 8.79 +/- 3.32 degrees at apex level, respectively, of the septum wall, respectively. This study shows significant correlation between the angle of 3-dimensional trajectory (small ef, Cyrillic) with the angle in short axis view (theta) of the septum wall at the apex level; and also with the angle in long axis view (chi) of the septum wall at base and mid levels. CONCLUSION: Due to the motion of the wall of the left ventricle in three dimensions, and the non-isotropic structure of myofibers, the angle of 3-dimensional trajectory was estimated using the speckle tracking method of 2-dimentional echocardiography images.

Assessment of left ventricular torsion in short axis view between healthy subjects and significant coronary artery disease patients

Coronary artery disease causes changes in biomechanical parameters and function of myocardial. Recently, torsion angle is one of the most important mechanical parameters. Therefore in this study, torsion angle in healthy subjects and LAD significant coronary artery disease patients, using echo tracking method in short axis view, was evaluated. In cross sectional study, 14 healthy subjects and 10 patients with significant stenosis of LAD were evaluated. Two dimensional echocardiography images were scanned in apical and basal parasternal short axis view were recorded. Successive ultrasonic images were processed by echo tracking under block matching algorithm and peak torsion angle were estimated. Difference between healthy group and patient group were extracted by using peak torsion angle by the confidence level of 95%. In this study, basal rotation angle, apical rotation angle and torsion angle in short axis view in significant coronary artery disease patients significantly decreased 33%, 44% and 38% relative to healthy subjects, respectively. Also time to reach peak torsion angle in LAD coronary artery stenosis patients increased 19% relative to healthy group. It seems, torsion angle in short axis view, can diagnose LAD coronary artery stenosis patients reative to healthy subject