Matsuoka Masako, Oki Takashi, Mishiro Yuichiro, Yamada Hirotsugu, Tabata Tomotsugu, Wakatsuki Tetsuzo, Ito Susumu
Second Department of Internal Medicine, School of Medicine, The University of Tokushima, Tokushima, Japan.
Am Heart J. 2002 Mar;143(3):552-8. doi: 10.1067/mhj.2002.121266.
This study was undertaken for the determination of the correlation between myocardial viability and regional systolic mitral annular motion velocity (MAV) response to dobutamine stress in patients with previous myocardial infarction (MI) with pulsed tissue Doppler scan imaging.
The study included 45 patients (mean age, 65 +/- 12 years) with previous MI with 1 major coronary lesion and 30 healthy individuals (mean age, 61 +/- 14 years). 99mTc-methoxyisobutylisonitrile scintigraphy was performed to divide the patients into 2 groups: the viability (+) group (n = 25) and the viability (-) group (n = 20). Dobutamine was infused (at 2, 5, 10, and 20 microg/kg/min), and the peak first and second systolic MAVs (Sw1 and Sw2, respectively) were measured at the level of the mitral annulus corresponding to the infarct regions in the MI group and to the 6 mitral annular sites in the control group. In addition, the left ventricular wall motion score index (WMSI) was determined with 2-dimensional echocardiography.
At baseline, the WMSI was significantly greater and the mean Sw1 and Sw2 were significantly lower in both the viability (+) and (-) groups than in the control group, but there were no significant differences between the viability (+) and (-) groups. After dobutamine infusion, the WMSI improved only in the viability (+) group. The mean Sw1 and Sw2 increased significantly with 2 microg/kg/min and 5 microg/kg/min of dobutamine, respectively, in the viability (+) group. With an increase in Sw1 of 2.0 cm/s or more with 5 microg/kg/min of dobutamine, viable myocardium was detected, with a sensitivity of 92% and a specificity of 90%. There were no significant increases in Sw1 or Sw2 in the viability (-) group with dobutamine infusion.
Viable left ventricular myocardium is identified with peak early systolic MAV during dobutamine infusion.
本研究旨在通过脉冲组织多普勒扫描成像，确定既往心肌梗死（MI）患者心肌活力与多巴酚丁胺负荷试验时二尖瓣环区域收缩期运动速度（MAV）反应之间的相关性。
本研究纳入45例既往有MI且有1处主要冠状动脉病变的患者（平均年龄65±12岁）和30名健康个体（平均年龄61±14岁）。通过99mTc-甲氧基异丁基异腈闪烁扫描将患者分为两组：存活心肌（+）组（n = 25）和存活心肌（-）组（n = 20）。静脉输注多巴酚丁胺（剂量为2、5、10和20μg/kg/min），测量MI组梗死区域对应二尖瓣环水平以及对照组6个二尖瓣环位点处的收缩期MAV峰值（分别为Sw1和Sw2）。此外，采用二维超声心动图测定左心室壁运动评分指数（WMSI）。
基线时，存活心肌（+）组和（-）组的WMSI均显著高于对照组，平均Sw1和Sw2均显著低于对照组，但存活心肌（+）组和（-）组之间无显著差异。多巴酚丁胺输注后，仅存活心肌（+）组的WMSI有所改善。存活心肌（+）组中，多巴酚丁胺剂量为2μg/kg/min和5μg/kg/min时，平均Sw1和Sw2分别显著增加。当多巴酚丁胺剂量为5μg/kg/min且Sw1增加2.0 cm/s或更多时，可检测到存活心肌，敏感性为92%，特异性为90%。多巴酚丁胺输注后，存活心肌（-）组的Sw1或Sw2无显著增加。
多巴酚丁胺输注期间，通过早期收缩期MAV峰值可识别存活的左心室心肌。
