小型猪低剂量多巴酚丁胺电影磁共振成像检测存活心肌

Detection of viable myocardium by low dose of dobutamine cine MR imaging in miniswine.

作者信息

Lu Minjie, Zhao Shihua, Wei Yunqing, Wang Cheng, Jiang Shiliang, Huang Lianjun, Zhang Yan, Mou Feng, Meng Liang, Ruan Yingmao

机构信息

Department of Radiology, Experimental Surgery, Department of Pathology, Cardiovascular Institute & Fuwai Hospital, CAMS & PUMC, Beijing 100037, China.

出版信息

Chin Med J (Engl). 2003 Jun;116(6):893-6.

PMID:12877802

Abstract

OBJECTIVE

To evaluate the diagnostic value of dobutamine stress magnetic resonance imaging (MRI) for myocardial viability.

METHODS

Ten male miniswines underwent left ventriculography and coronary angiography, followed by stenosis of the left circumflex coronary artery (LCX) using ameroid constrictor. More than one month later, left ventriculography and coronary angiography were performed again, followed by cine-MRI at rest and during stress with incremental dose of dobutamine 5 - 20 micro g.kg(-1).min(-1). Traditional and/or breath-hold cine-MRI were used to evaluate regional left ventricular wall motion, corresponding to basal, midventricular and apical short-axis tomograms. Regional wall motion score index (WMSI) was calculated. The miniswines were finally sacrificed for pathological examination. Triphenyl tetrazolium chloride (TTC) delineated myocardial infarction. Microscopy was used to identify myocardial cellular changes.

RESULTS

One pig died, one pig suffered from aneurysm and another showed no negative findings. The other seven pigs were found with hypokinetic (n = 4) or akinetic (n = 3) myocardial regions related to stenosed LCX. Their mean WMSI at rest for the lateral and posteroinferior walls (ischemic regions) of the left ventricle was 2.27 +/- 0.32, as compared with 1.00 +/- 0.00 (P < 0.01) for the corresponding nonischemic anteroseptal regions. Further, the mean WMSI for the ischemic regions was 2.27 +/- 0.32 at rest compared with 1.40 +/- 0.39 (P < 0.01) at the dose of dobutamine 5 micro g.kg(-1).min(-1). However, the mean WMSI at the doses of dobutamine 10 and 20 micro g.kg(-1). min(-1) were 1.70 +/- 0.76 and 1.75 +/- 0.83, respectively, with no significant difference as compared with the mean WSCI at rest (P > 0.05). The pathologic examination showed viable myocardium at the ischemic regions.

CONCLUSION

Low-dose dobutamine (5 micro g.kg(-1).min(-1)) recovers hypokinetic or akinetic myocardial regions, and dobutamine stress MRI can be used to detect myocardial viability.

摘要

目的

评估多巴酚丁胺负荷磁共振成像（MRI）对心肌存活性的诊断价值。

方法

10只雄性小型猪接受左心室造影和冠状动脉造影，随后使用阿霉素缩窄器使左旋冠状动脉（LCX）狭窄。一个多月后，再次进行左心室造影和冠状动脉造影，然后在静息状态下以及使用递增剂量的多巴酚丁胺5 - 20μg·kg⁻¹·min⁻¹进行负荷试验时进行电影MRI检查。采用传统和/或屏气电影MRI评估左心室壁节段运动，对应于基底、心室中部和心尖短轴断层图像。计算节段壁运动评分指数（WMSI）。最终处死小型猪进行病理检查。用氯化三苯基四氮唑（TTC）勾勒出心肌梗死区域。通过显微镜观察确定心肌细胞变化。

结果

1只猪死亡，1只猪出现动脉瘤，另1只未发现异常。其他7只猪发现与狭窄的LCX相关的心肌运动减弱（n = 4）或运动消失（n = 3）区域。左心室侧壁和后下壁（缺血区域）静息时的平均WMSI为2.27±0.32，而相应的非缺血前间隔区域为1.00±0.00（P < 0.01）。此外，缺血区域静息时的平均WMSI为2.27±0.32，在多巴酚丁胺剂量为5μg·kg⁻¹·min⁻¹时为1.40±0.39（P < 0.01）。然而，多巴酚丁胺剂量为10和20μg·kg⁻¹·min⁻¹时的平均WMSI分别为1.70±0.76和1.75±0.83，与静息时的平均WSCI相比无显著差异（P > 0.05）。病理检查显示缺血区域存在存活心肌。