应用舒张期应变负荷超声心动图法评价左室心肌缺血

目的 对运动负荷5 min后的患者,用舒张期应变超声心动图法检测心肌缺血引起的左室舒张功能碍障,客观的判定局部心肌缺血.方法 对37例怀疑缺血性心脏病患者(平均年龄65岁±9岁),在运动负荷前及负荷5 min后,分别在心尖部长轴切面,四腔心切面及二腔心切面的各室壁中间段合计6个左室节段上获取应变曲线.在各节段中,测定主...

Evaluation of Left Ventricular Myocardial Ischemia with Diastole Strain Echocardiography after Treadmill Exersise

Objective Application diastolic strain echocardiography methods to objective determine regional myocardial ischemia.Methods 37 patients with suspected coronary artery disease(CAD) were enrolled.Strain echocardiographic images were acquired at mid segments of all the six left ventricular walls before and 5 minutes 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×100%.The ratio of SDI before exercise to that after exercise was defined as SDI ratio and compared with exercise SPECT as reference standard to detect myocardial ischemia.Results A total of 222 segments were evaluated by strain echocardiography.So as the results of exercise SPECT,163 segments were classified as non-ischemic segments;59 as ischemic segments.In ischemic segments,there were significant decreases of SDI from before to after exercise,whereas there were no significant differences of SDI from before to after exercise in non-ischemic segments.SDI ratio was significantly decreased in ischemic segments,but not in non-ischemic segments.Based upon the results of exercise SPECT,with a cutoff value of 0.51,SDI ratio yielded a sensitivity of 91% and a specificity of 89% to detect myocardial ischemia in the receiver-operating-characteristics.Conclusion Diastole strain echocardiography provides quantitative assessment of myocardial ischemia by detecting post-ischemic regional LV delayed relaxation even 5 minutes after exercise.