负荷心肌灌注显像中腺苷诱导的ST段下移的临床应用意义

 目的 探讨腺苷负荷诱导的ST段下移的发生特点、与腺苷负荷—静息心肌灌注显像（MPI）心肌缺血之间的关系及其在冠心病（CAD）诊断中的作用。方法125例疑似或确诊的CAD患者行一日法腺苷负荷—静息MPI。腺苷注射后出现ST段水平样或下斜下移≥1.0 mm定义为缺血心电图阳性表现，MPI出现可逆或不可逆显像剂摄取降低作为心肌缺血评价标准，观察腺苷负荷诱导的ST段下移与MPI显像提示缺血之间的相互关系。48例患者行冠脉造影术，3支主要血管中至少有1支血管管腔直径狭窄≥50%作为阳性的诊断标准。结果 125例患者中42例（33.6%）出现心电图阳性改变，女性发生率高于男性（P＜0.05）；腺苷负荷ST段下移与心肌MPI显像心肌缺血间无明显相关性（P＞0.05）。冠脉造影阳性的32例患者中，25例有MPI心肌缺血，其中14例伴有心电图改变；而冠脉造影阴性的16例患者中，MPI显像正常12例，其中10例腺苷负荷心电图无缺血改变。结论 腺苷注射诱导的心电图ST段改变能为腺苷心肌MPI提供有价值的诊断信息。

Clinical Significance of Adenosine-induced ST-segment Depression during Myocardial Perfusion Imaging Stress Testing

Objective To investigate the clinical significance of adenosine-induced ST depression in diagnosis of coronary artery disease(CAD) during myocardial perfusion imagine(MPI) stress testing.Methods Totally 125 cases of suspected or diagnosed CAD patients were selected and went through the adenosine stress-rest protocol.Single-photon emission computed tomography(SPECT) was employed for the analysis.The presence of a ≥1 mm horizontal or down-sloping ST-segment depression after adenosine injection was interpreted as ischemia electrocardiograms.The SPECT perfusion analysis was performed by two experienced doctors.Reversible or irreversible defect verified in different sections was considered as myocardial ischemia.48 patients underwent coronary angiography,and significant stenosis was defined as ≥50% stenosis in at least one of the three major coronary arteries.Results Among 125 cases,42 patients showed ischemic ST segment depression during adenosine stress myocardial imaging;the prevalence in women was much higher than in men(χ2=8.54,P < 0.05).There was no significant difference between perfusion defect detected by the MPI scan for patients with or without ST-segment depression(χ2=1.76,P > 0.05).Of 32 patients with coronary stenosis,25 had SPECT perfusion abnormality defects,14 of them accompanied with ischemic ECG changes,which was higher than patients without ischemic ECG changes.Of 16 patients without coronary stenosis,12 had normal perfusion,10 without ischemic ECG changes.Conclusion Examining and reporting the results of electrocardiographic changes that occur in single-photon emission computed tomographic MPI can provide valuable information in diagnosis of CAD.