背向散射技术结合多巴酚丁胺负荷试验检测不同部位冠状动脉狭窄

目的探讨背向散射技术结合多巴酚丁胺负荷试验(DSE)能否提高对不同部位冠状动脉狭窄的检测率。方法记录32例临床疑诊为冠心病的患者在不同剂量多巴酚丁胺负荷下左室乳头肌水平短轴观的背向散射积分,按冠状动脉造影结果将心肌节段分组,比较各组心肌在各剂量负荷下背向散射积分周期变异(CVIB)值的变化。结果和正常冠状动脉供血心肌节段相比,狭窄冠状动脉供血心肌节段的CVIB值在静息状态和小剂量多巴酚丁胺负荷下无显著差异,但在大剂量负荷下明显降低。以DSECVIB<4.8dB作为检测冠状动脉狭窄的阈值,对于左前降支病变,DSECVIB法可提高敏感性、特异性和准确率;对于左旋支和右冠状动脉病变,DSECVIB法未能提高检测的敏感性,而提高了特异性和准确率。结论背向散射技术与传统DSE联合应用可提高DSE对不同部位冠状动脉狭窄的检测率,尤其对于左前降支的病变。

Detection different coronary artery stenosis by integrated backscatter combined with dobutamine stress echocardiography

Objective To investigate whether the sensitivity and specificity of detecting different coronary artery stenosis could be improved by cyclic variation of integrated backscatter(CVIB) under dobutamine stress echocardiography (DSE).Methods Thirty-two patients with suspected coronary artery disease underwent DSE before selected coronary angiography.CVIB of the left ventricular myocardial segments supplied by three coronary branches was analyzed at the baseline and the stages of DSE.Results Comparing with the value of baseline and low dose stages,in ischemic myocardium,CVIB decreased under high dose.While in non-ischemic myocardium,CVIB showed no difference at all stages of DSE.Taking CVIB< 4.8 dB as the cutoff point,the sensitivity and accuracy rate of detecting left anterior descending coronary artery (LAD) stenosis by the integrated backscatter under DSE was elevated,but for the right coronary artery and left circumflex artery lesions,DSE-CVIB did not improve the sensitivity,but specificity and accuracy.Conclusions Integrated backscatter combined with DSE is valuable in detecting different parts of ischemia in myocardium,especially in detecting LAD lesions.