实时三维斑点追踪显像技术检测犬顿抑心肌左心室舒张功能延迟恢复

Real-time three-dimensional speckle tracking imaging in detection of left ventricular delayed relaxation of stunned myocardium in canines

目的应用实时三维斑点追踪显像技术(3D-STI)检测犬顿抑心肌左心室舒张功能的延迟恢复。方法结扎12只成年杂种犬左冠状动脉前降支,15min后行再灌注;分别于缺血前、缺血5min和15min、再灌注30min、60min、90min及120min采集心尖切面三维图像,检测缺血及非缺血心肌峰值纵向应变(LSpeak)、主动脉瓣关闭时的纵向应变、舒张前1/3时点纵向应变,根据公式计算应变显像舒张指数(SI-DI)。结果缺血5min和15min缺血心肌LSpeak和SI-DI显著降低,随再灌注时间延长而逐渐恢复;LSpeak于再灌注120min时恢复正常,SI-DI于再灌注120min时仍低于正常;缺血5min和15min非缺血节段心肌LSpeak和SI-DI升高,均于再灌注30min恢复正常。结论应用3D-STI可评价犬顿抑心肌缺血及再灌注阶段左心室局部心肌舒张功能的延迟恢复。

Objective To assess the left ventricular delayed relaxation of stunned myocardium with real time three-dimensional speckle tracking imaging（3D-STI） in canines.Methods Left anterior descending arteries of 12 canines were ligated to induce myocardial ischemia for 15 min,followed by reperfusion.The peak longitudinal strain（LSpeak） and strain imaging diastolic index（SI-DI） of ischemic and non-ischemic myocardium were measured and calculated using 3D-STI before ischemia,5 min and 15 min after ischemia,as well as 30 min,60 min,90 min and 120 min after reperfusion.Results LSpeak and SI-DI decreased in ischemic myocardium 5 min and 15 min after ischemia and both recovered with reperfusion time going.LSpeak returned to normal while SI-DI did not 120 min after reperfusion.In non-ischemic myocardium,LSpeak and SI-DI increased after ischemia 5 min,15 mm and both recovered 30 min after reperfusion.Conclusion 3D-STI has application value for evaluation on the delayed relaxation of regional left ventricle in stunned myocardial in canines.