Alterations of myocardial regional motion time variance caused by different extent of coronary artery stenosis / 中华超声影像学杂志

ABSTRACT

Objective To access the alterations of ischemic myocardial regional motion time caused by different extent of coronary artery stenosis by 2D-strain technique. Methods Two-dimensional images were acquired of the standard parasternal and apical (4-chamber,2-chamber and long-axis) views and short-axis views (mitral annulus, papillary muscle and apex) in 140 patients with coronary artery disease. All left ventricular segments were divided into 5 groups according to coronary stenosis seen on angiographynormal,25% -49% ,50% -74% ,75% -99% and 100%. The time to segmental systolic peak strain, systolic peak strain rate, end systolic strain, early diastolic peak strain rate and late diastolic peak strain rate in longitudinal, radial, circumferential directions and the systolic peak rotation, systolic peak rotation rate, early diastolic rotation rate,late diastolic rotation rate were analyzed with EchoPAC offline software. Results In longitudinal direction,compared with normal group,the time to early diastolic peak strain rate of segments with 75% - 99% coronary stenosis increased significantly, the time to systolic peak strain rate, early diastolic peak strain rate of segments with occluded artery were significantly delayed compared with the other 4 groups (P ＜0.05). In radial, circumferential directions, the time to systolic peak strain, systolic peak strain rate,late diastolic peak strain rate of segments with 25% - 49% was shorter than that of normal segments. Those indices for segments with 50% - 74% coronary stenosis were delayed compared with segments with 25% - 49% stenosis, however, those for segments with 75% - 99% coronary stenosis showed some improvement in the comparison with segments with 50% - 74% stenosis. All time indices for segments with occluded arteries were delayed ( P ＜0.05). About rotation, the time to the systolic peak rotation,systolic peak rotation rate,early diastolic peak rotation rate with 25% -49% stenosis was shorter than those of normal segments, the time to systolic peak rotation and early diastolic peak rotation rate for segments with 75% - 99% stenosis improved compared with segments with 50% - 74% stenosis.Conclusions 25% -49% coronary stenosis could lead to alterations of peak myocardial systole and diastole motion time in radial,circumferential and rotation directions,and ≥75% coronary stenosis caused the all 4 directions motion delays. Also the time indices for segments with 75% - 99% coronary stenosis showed some improvement in the comparison with segments with 50% -74% coronary stenosis.