小剂量多巴酚丁胺负荷试验中应变率显像与组织速度显像技术评价存活心肌舒张功能

Evaluation of Diastolic Function of Viable Myocardium Under Low Dose Dobutamine Stress Using Strain Rate Imaging and Tissue Velocity Imaging

目的:使用应变率显像(SRI)与组织速度显像(TVI)技术检测小剂量多巴酚丁胺负荷超声试验(LDDSE)中陈旧性心肌梗死(OMI)患者左室节段舒张功能变化,探讨SRI及TVI技术检测OMI患者存活心肌的临床价值。方法:对25例OMI患者分别于静息及5,10μg/(kg.min)多巴酚丁胺负荷时获取心尖两腔、三腔、四腔TVI图像存盘,脱机分析左室前壁、下壁、前室间隔、后壁、后室间隔、侧壁基底段、中段心内膜下心肌SRI及TVI参数:①SRI测量参数:舒张早期峰值应变率(SRe),舒张晚期峰值应变率(SRa),计算舒张早、晚期峰值应变率比值(SRe/SRa);②TVI测量参数:舒张早期峰值运动速度(Ve),舒张晚期峰值运动速度(Va),计算舒张早、晚期峰值运动速度比值(Ve/Va)。于经皮腔内冠状动脉成形术(PTCA)后4-6周复查常规超声心动图,根据室壁运动分析方法计分判别存活心肌。结果:静息状态下,与正常节段比较,存活心肌组与非存活心肌组SRe、Ve均显著减低(P<0.05),存活心肌组与非存活心肌组之间SRe、Ve则无显著差异。与静息状态比较,5,10μg/(kg.min)负荷时,存活心肌组各室壁节段SRe、SRe/SRa、Ve、Ve/Va均显著增加,而非存活心肌组上述各指标均无明显改变(P>0.05);5μg/(kg.min)负荷时,以SRe≥1.21 s-1,Ve≥5.98 cm/s为截断值,与Ve比较,SRe识别存活心肌的敏感性、特异性显著增加;10μg/(kg.min)负荷时,与Ve比较,SRe识别存活心肌的敏感性与特异性无差别。结论:使用SRI及TVI技术可在LDDSE中定量评价OMI患者心肌舒张功能,具有较高的敏感性及特异性,但5μg/(kg.min)负荷时SRe的敏感性及特异性更高。

Objective.. To explore the clinical value of strain rate imaging （SRI） and tissue velocity imaging （TVI） technology in evaluating the left ventricular diastolic function in old myocardial in- farction （OMI） patients during low dose dobutamine stress echocardiography （DSE） test. Methods： Twenty-five patients with OMI received low dose DSE test using SRI and TVI at base- line, 5 and 10 μg/（kg - min） dobutamine stress under 2-chamber, 3 chamber and 4-chamber apical view. SRI and TVI indices include early diastolic peak strain rate（SRe）, late diastolic peak strain rate （SRa）, early diastolic peak velocity（Ve）, as well as late diastolic peak velocity （Va） were measured, and the ratio of SRe to SRa（SRe/SRa） and the ratio of Ve to Va（Ve/Va） were calculated. Results. At baseline, compared with the normal, SRe and Ve of viable myocardium （group V） and non-viable myocardium group （group NV） decreased significantly （P〈0.05）, but there was no difference between group V and group NV. Compared with those at baseline, SRe, SRe/SRa, Ve and Ve/Va of group V increased significantly at 5 and 10 μg/（kg ·min） dobu- tamine stress （P〈0.05）, however, there was no change in group NV. Conclusion. In LDDSE, SRI and TVI can evaluate the left ventricular diastolic function in OMI patients. SRe and Ve both have high sensitivity and specificity to detect viable myocardium, however, compared with Ve, SRe has higher sensitivity and specificity at 5 μg/（kg·min） stress.