Zammarchi A, Pitscheider W, Crepaz R, Oberhollenzer R, Erlicher A, Unterhuber E, Osele L, Braito E
Divisione di Cardiologia, Ospedale Regionale Generale di Bolzano.
G Ital Cardiol. 1994 Sep;24(9):1103-13.
Reduced septal uptake of 201-Thallium in patients with left bundle branch block is reported in literature as having a variable frequency (between 14% and 100%) and in such patients the value of exercise Thallium-scintigraphy for the diagnosis of the left anterior descending coronary artery disease is limited by the great number of false-positive tests. The aim of this study was to assess the prevalence and the diagnostic sensitivity of this septal defect in a group of patients with left bundle branch block.
We evaluated the exercise 201-Thallium myocardial scintigraphy of 54 patients with a stable left bundle branch block. The clinical and/or echocardiographic evaluation excluded the presence of primitive, valvular and hypertensive cardiomyopathies and of previous myocardial infarction. The planar myocardial scintigraphic imaging was acquired according to the "stress-redistribution" protocol. Only 37 patients underwent an echocardiographic examination and following clinical and/or scintigraphic indications; 27 patients underwent a coronary angiography for the evaluation of coronary stenosis.
The 201-Thallium imaging showed septal defects in 36 patients (67%) and the presence of defects in other segments in 14 patients. The echocardiographic evaluation showed an interventricular septal defect contraction abnormality in 19 cases in the 27 patients with septal defect and in 4 cases in the 10 patients with negative scintigraphy (Fisher NS). Twenty-seven patients (23 with- and 4 without septal defect) underwent a coronary angiography, which showed in 6 cases critical stenosis of the left descending anterior artery, in 5 of the right coronary, in 3 of the Circumflex artery and in 16 normal coronary angiograms. The presence of the septal uptake defect showed a diagnostic sensitivity and specificity for the detection of the left anterior descending coronary artery disease of respectively 67% and 52% (whereas using a semi-quantitative analysis of 100% and 19%). The scintigraphy showed a sensitivity and specificity for the detection of the right coronary artery disease of respectively 80% and 100% and for the circumflex coronary artery stenosis of 0% and 100%.
We found a high prevalence of septal perfusion defects (67%) and this results shows a high sensitivity but a low specificity for the diagnosis of the left anterior descending coronary disease; the semi-quantitative analysis improves the sensitivity, but leads to a further reduction of the specificity. The female patients had a prevalence (70%) similar to the general population but demonstrated a higher percentage of false-positive. The 201-Thallium scintigraphy has a high diagnostic accuracy for the detection of the right coronary artery stenosis, while it is less accurate regarding the circumflex artery disease.
文献报道，左束支传导阻滞患者铊-201的间隔摄取减少，其出现频率不一（14%至100%），在此类患者中，运动铊闪烁扫描对左前降支冠状动脉疾病的诊断价值因大量假阳性检查而受限。本研究旨在评估一组左束支传导阻滞患者中这种间隔缺损的患病率及诊断敏感性。
我们评估了54例稳定型左束支传导阻滞患者的运动铊-201心肌闪烁扫描。临床和/或超声心动图评估排除了原发性、瓣膜性和高血压性心肌病以及既往心肌梗死的存在。平面心肌闪烁扫描成像按照“负荷-再分布”方案进行采集。仅37例患者根据临床和/或闪烁扫描指征接受了超声心动图检查；27例患者接受了冠状动脉造影以评估冠状动脉狭窄情况。
铊-201成像显示36例患者（67%）存在间隔缺损，14例患者其他节段存在缺损。超声心动图评估显示，27例有间隔缺损的患者中有19例室间隔缺损收缩异常，10例闪烁扫描阴性的患者中有4例出现异常（费舍尔检验无显著差异）。27例患者（23例有间隔缺损，4例无间隔缺损）接受了冠状动脉造影，结果显示6例左前降支动脉严重狭窄，5例右冠状动脉狭窄，3例回旋支动脉狭窄，16例冠状动脉造影正常。间隔摄取缺损的存在对检测左前降支冠状动脉疾病的诊断敏感性和特异性分别为67%和52%（而采用半定量分析时分别为100%和19%）。闪烁扫描对检测右冠状动脉疾病的敏感性和特异性分别为80%和100%，对回旋支冠状动脉狭窄检测的敏感性和特异性分别为0%和百分之百。
我们发现间隔灌注缺损的患病率很高（67%），这一结果显示对左前降支冠状动脉疾病的诊断敏感性高但特异性低；半定量分析提高了敏感性，但导致特异性进一步降低。女性患者的患病率（70%）与总体人群相似，但假阳性比例更高。铊-20闪烁扫描对检测右冠状动脉狭窄具有较高的诊断准确性，而对回旋支动脉疾病的诊断准确性较低。
