Zhu Hong, Hozumi Takeshi, Takemoto Yasuhiko, Takagi Yasuhiro, Negishi Kazuaki, Abo Koji, Sugioka Kenichi, Matsumura Yoshiki, Otsuka Ryo, Yoshitani Hidetoshi, Nakao Mitsuru, Yoshiyama Minoru, Yoshikawa Junichi
Department of Internal Medicine and Cardiology, Osaka City University Graduate School of Medicine, Osaka.
J Cardiol. 2006 Apr;47(4):165-72.
The feasibility of detecting persistent regional left ventricular abnormal relaxation due to myocardial ischemia using strain echocardiography several minutes after exercise was investigated.
Consecutive 27 patients (mean age 65 +/- 9 years, 21 males, 6 females) with suspected coronary artery disease were enrolled. Strain echocardiographic images were acquired at the mid segments of the left ventricular wall before and 5 min after exercise in the apical long-axis, two-chamber and four-chamber views. Strain curves were obtained at each segment, and peak values of strain at the closure of aortic valve (A) and at one third of diastolic duration (B) were measured. Strain diastolic index (SDI) was calculated as (A - B)/A X 100%. The ratio of SDI before exercise to that after exercise was defined as the SDI ratio and compared with exercise thallium-201 single photon emission computed tomography (SPECT) as the reference standard to detect myocardial ischemia.
A total of 162 segments were evaluated. Based on the results of exercise SPECT, 119 segments were classified as non-ischemic segments, and 43 as ischemic segments. Ischemic segments showed significant decreases in SDI before and after exercise, whereas non-ischemic segments showed no significant differences in SDI before and after exercise. SDI ratio was significantly decreased in ischemic segments, but not in non-ischemic segments. SDI ratio with a cut off value of 0.51 had a sensitivity of 91% and a specificity of 89% to detect myocardial ischemia in the receiver-operating characteristics. Conclusions. Strain echocardiography can provide quantitative assessment of myocardial ischemia by detecting post-ischemic regional left ventricular delayed relaxation even 5 min after exercise.
研究运动数分钟后使用应变超声心动图检测因心肌缺血导致的持续性局部左心室舒张异常的可行性。
纳入27例疑似冠心病患者（平均年龄65±9岁，男性21例，女性6例）。在运动前及运动后5分钟，于心尖长轴、两腔心和四腔心切面获取左心室壁中段的应变超声心动图图像。在每个节段获取应变曲线，并测量主动脉瓣关闭时（A）和舒张期三分之一时（B）的应变峰值。应变舒张指数（SDI）计算为（A - B）/A×100%。将运动前与运动后的SDI比值定义为SDI比值，并与运动铊-201单光子发射计算机断层扫描（SPECT）作为检测心肌缺血的参考标准进行比较。
共评估162个节段。根据运动SPECT结果，119个节段被分类为非缺血节段，43个为缺血节段。缺血节段运动前后的SDI显著降低，而非缺血节段运动前后的SDI无显著差异。缺血节段的SDI比值显著降低，而非缺血节段则无降低。在受试者工作特征曲线中，SDI比值截断值为0.51时，检测心肌缺血的敏感性为91%，特异性为89%。结论：应变超声心动图可通过检测运动后5分钟即使缺血后局部左心室延迟舒张来提供心肌缺血的定量评估。
