Objective To probe into the speckle tracking imaging assessment of the influence on the left ventricular twist by myocardial bridge of the left anterior descending (LAD)coronary artery.
Methods 21 patients with symptoms with myocardial bridge of LAD, 19 patients with myocardial bridge (MB) of LAD accompany with stenosis of proximal mural coronary artery verified by coronary angiogram and 30 patients of the control group were entrolled in this study. The two-dimensional loop-cinec was obtained at the left ventricular short-axis view of such groups above. The peak subendocardial and subepicardial global rotation at the level of basal and apical planes were compared among three groups.
Results (1) As seen from the apex, left ventricle performed a wringing motion with a clockwise rotation at the base and countclockwise rotation at the apex in all groups. (2) The peak global rotation of the subendocardium was obviously greater than the one of the subepicardium in the basal and apical planes in all subjects (p<0.05); the peak subepicardium left ventricular twist was also lower than the peak subendocardium. (3) There were no differences in the peak global rotation of the subendocardium and the subepicardium between the control group and the MB group of LAD (p>0.05). (4) In the MB of LAD accompany with stenosis of proximal mural coronary artery groups, the peak global rotation of the subendocardium and the subepicardium in the apical plane are significantly lower than that of the control group and the groups with MB of LAD (4.07±2.09, 2.31±0.92 vs 6.26±1.47, 3.42±1.15 vs 5.81±1.56, 3.12±1.05; 7.76±2.82, 4.26±1.36 vs 10.5±2.56, 5.78±1.45 vs 9.72±2.13, 5.35±1.21, p<0.05), the peak subepicardium and subendocardium left ventricular twist were also impaired, but have no difference in the basal plane.
Conclusions The global left ventricular systolic function of patients with symptoms with MB of LAD accompany with stenosis of proximal mural coronary artery are impaired, the atheromatous plaque maybe work for this.