小剂量多巴酚丁胺负荷下运用校正背向散射声学参数检测存活心肌

目的探讨在小剂量多巴酚丁胺负荷(LDDSE)下运用校正背向散射声学参数能否提高检测存活心肌的敏感性和特异性.方法心肌梗死患者46例,按照PTCA术后室壁运动改善状况将心肌节段分为存活心肌组和非存活心肌组,比较2组在PTCA前LDDSE下的心肌背向散射指标.结果 LDDSE下存活心肌的CVIB及校正CVIB值均高于静息状态,而非存活心肌的CVIB与校正CVIB值在两种状态下无明显差异.以CVIB＞5.0 dB和校正CVIB＞3.8 dB作为判断存活心肌的标准,敏感性、特异性、准确性分别为82.1%和85.7%、68.9%和72.4%、77.6%和81.2%.二维室壁运动评分法判断存活心肌的敏感性、特异性、准确性分别为76.9%、75.9%、76.5%.结论背向散射技术结合小剂量多巴酚丁胺负荷超声心动图能较好地定量评价存活心肌,相对于二维室壁运动评分法,是更为客观准确的评价室壁运动的方法.

Detection of viable myocardium by corrected integrated backscatter parameters under low dose dobutamine stress echocardiography

Objective To certificate whether the sensitivity and specificity of detecting viable myocardium could be enhanced by using corrected integrated backscatter indices (CVIB and phase-weighed CVIB) under low dose dobutamine stress echocardiography (LDDSE). Methods LDDSE was executed on 46 patients with myocardial infarction before percutaneous coronary angiography (PTCA). CVIB and corrected CVIB, as well as wall motion index (WMI), of anterior wall, anterior septum, inferior wall and posterior wall of the left ventricle were measured under LDDSE and baseline. Results CVIB and corrected CVIB of the viable myocardium under LDDSE were higher than that at baseline, but CVIB and corrected CVIB of the non-viable myocardium were not significantly different from baseline. Taking CVIB>5.0 dB and corrected CVIB>3.8 dB as the cut-off point, the sensitivity, specificity and accuracy of the integrated backscatter indices under LDDSE in predicting viable myocardium were 82.1% and 85.7%, 68.9% and 72.4%, 77.6% and 81.2%, respectively. Conclusion Integrated backscatter combined with LDDSE is valuable in detecting viable myocardium. Comparing to two-dimensional wall motion index, integrated backscatter index is superior with better objectivity and accuracy.