摘要
目的评价多巴酚丁胺对正常和狭窄冠状动脉微循环的直接效应,并与腺苷对比。方法实验应用9条健康杂种犬,制备左前降支静息无血流限制性狭窄。在静息状态和左冠状动脉主干内连续输注多巴酚丁胺(2mg·kg^-1·min^-1)和腺苷(5mg·kg^-1·min^-1)时,进行间断谐波心肌对比成像评估心肌血流容积(A)和心肌血流速度(b),并同步应用放射性标记微球测定心肌血流量(MBF),计算心率血压乘积和心肌血管阻力(MVR)。结果两种药物引起正常和狭窄冠状动脉供血区MBF明显增加和MVR明显降低(P<0.05)。在正常冠状动脉供血区,腺苷对A无明显影响,MVR的降低完全是阻力血管的扩张所致(99%),MBF增加主要是由于b的加快(△β/△A=13.6);多巴酚丁胺可引起部分A增加(28%),使总MVR降低中的32%来自这种毛细血管征募,但MBF增加主要还是由于b的加快(△β/△A=5.9)。在狭窄冠状动脉供血区,两种药物引起MBF增加的程度相同,MBF增加均完全是由于b的加快;多巴酚丁胺和腺苷引起毛细血管的关闭分别导致14%和15%心肌毛细血管阻力的增加。结论经冠状动脉内直接给药物时,多巴酚丁胺对冠状动脉微循环的直接效应与腺苷对冠状动脉微循环的直接效应非常相近,MBF增加主要由于心肌血流速度的增快所致。
Objective To evaluate thedirect effects of dobutamine as compared to adenosine on the coronary microcirculation in both normal and stenotic segments using myocardial contrast echocardiography （MCE）. Methods Left anterior descending （LAD） coronary artery stenosis, which was not flow limiting at rest, was established in 9 dogs. At the baseline and during intracoronary infusion of dobutamine （2 mg· kg^-1·min^-1） and adenosine （5mg· kg^-1·min^-1）, the radiolabeled microsphere （RM） -derived myocardial blood flow （MBF） were determined, and the double product （DP） and myocardial vascular resistance （MVR） were calculated. MCE was performed to determine the myocardial blood volume （MBV, represented by A） and microbubble velocity （β）. Results As compared to the baseline level, the MBF increased and MVR decreased significantly in both the normal and abnormal beds during infusion of both drugs （P〈0.05）. In the normal bed, adenosine had no effect on MBV, the decrease in MVR was the result of decreased＇arteriolar （plus venular） resistance, and the increase in MBF was predominately due to the increase in b （Δβ/ΔA=13.6）. Dobutamine caused a 28% increase in MBV, responsible for 32% of the decrease in the total MVR, but the increase in MBF arose mainly from the increase in b （Δβ/ΔA=5.9）. In the abnormal bed, both the drugs caused a similar increase in MBF entirely by increasing b, and 14% and 15% of the increases in capillary resistance were associated with the capillary derecruitment during administration of dobutamine and adenosine, respectively. Conclusion The direct effects of intracoronary dobutamine infusion on the coronary microcirculation are similar to that of adenosine, and the increase in MBF occurs mostly as the result of increased myocardial blood velocity.
出处
《南方医科大学学报》
CAS
CSCD
北大核心
2008年第3期348-352,共5页
Journal of Southern Medical University
基金
国家“863”计划项目(2006AA02Z478)~~
关键词
多巴酚丁胺
腺苷
心肌对比超声
dobutamine
adenosine
myocardial contrast echocardiography
