多巴酚丁胺负荷下背向散射技术检测存活心肌的临床研究

The Echocardiographic Detection of the Viable Myocardium by Integrated Backscatter Characterization Under Dobutamine Stress

目的 运用背向散射技术结合小剂量多巴酚丁胺负荷超声心动图对 3 2例慢性冠心病患者不同类型的心肌进行分析 ,探讨二者相结合检测存活心肌价值。方法 测量不同负荷阶段 ( 0、5、10、2 0 μg/kg·min注药速度 )胸骨旁左心室乳头肌水平短轴切面的 4个节段 (前壁、下壁、前室间隔及后壁 )的CVIB和CVIB % ,PTCA术后随访二维超声。结果 对照组 (A组 )及非存活心肌组 (B组 )的CVIB和CVIB %在小剂量多巴酚丁胺负荷状态下无显著变化 ,而存活心肌组 (C组 )CVIB和CVIB %均在 5～ 10 μg/kg·min时增加至 2 0 μg/kg·min。结论 慢性冠心病患者的心肌背向散射积分参数在小剂量多巴酚丁胺负荷状态下呈现出有意义的改变 。

Objective To discuss the myocardial integrated backscatter (IBS) characterization in patients with chronic coronary artery disease (CAD) during the low dose dobutamine stress echocardiography (DSE). Methods 32 patients with CAD underwent 4 stages low dose DSE (0,5,10 and 20μg/kg·min dobutamine infusion). The cardiac variation of IB (CVIB) and calibrated CVIB (CVIB%) were measured in different segments (anterior wall, inferior wall, anterior septum, and post wall of left ventricle) in different stages. Results In the viable segments (Group C), CVIB and CVIB% increased from low level in early stage (5～10μg/kg·min) to the endpoint (20μg/kg·min), while it maintained high level in control segments (Group A). Both CVIB and CVIB% were lower in non-viable segments (Group B) than in Group A without variation during all stages. Conclusion The indexes of IBS were significant for the quantitative evaluation of the contractility of myocardium in CAD patients, especially for the viable myocardium.