Hartley Craig J, Reddy Anilkumar K, Michael Lloyd H, Entman Mark L, Taffet George E
Department of Medicine, Section of Cardiovascular Sciences, Baylor College of Medicine and The Methodist DeBakey Heart & Vascular Center, Houston, TX 77030, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:1094-7. doi: 10.1109/IEMBS.2009.5332488.
Mice are now commonly used as models of human cardiovascular diseases and conditions, but it is challenging to measure blood flow velocity in small vessels such as coronary arteries. Accordingly, we have developed a method using a 2 mm diameter 20 MHz pulsed Doppler probe applied to the chest of anesthetized mice to measure left main coronary blood flow velocity noninvasively. We also found that coronary flow velocity could be increased from baseline (B) to hyperemic (H) levels by changing the concentration of isoflurane gas anesthesia from 1% to 2.5% in oxygen. We used the ratio B/H to estimate coronary flow reserve (CFR) in young, adult, and old mice and in mice with obesity, atherosclerosis, pressure overload hypertrophy, and coronary artery occlusion. We found that B/H increases with age from 2.4 (young) to 3.6 (old) and is decreased to as low as 1.1 by all forms of heart and vascular disease studied. We conclude that CFR can be measured noninvasively and serially in mice as their cardiovascular systems adapt and remodel to various imposed or natural conditions, and that coronary flow reserve may be a good index of overall cardiac function in mice and potentially in man.
小鼠现在常用于作为人类心血管疾病和病症的模型，但在诸如冠状动脉等小血管中测量血流速度具有挑战性。因此，我们开发了一种方法，使用直径2毫米、20兆赫兹的脉冲多普勒探头应用于麻醉小鼠的胸部，以无创测量左冠状动脉主干血流速度。我们还发现，通过将异氟烷气体麻醉在氧气中的浓度从1% 变为2.5%，冠状动脉血流速度可以从基线（B）增加到充血（H）水平。我们使用B/H比值来估计年轻、成年和老年小鼠以及患有肥胖症、动脉粥样硬化、压力超负荷肥大和冠状动脉闭塞的小鼠的冠状动脉血流储备（CFR）。我们发现，B/H随年龄增长从2.4（年轻）增加到3.6（老年），并且在所研究的所有形式的心脏和血管疾病中降低至低至1.1。我们得出结论，随着小鼠心血管系统适应和重塑各种施加的或自然的条件，可以在小鼠中无创且连续地测量CFR，并且冠状动脉血流储备可能是小鼠乃至潜在人类整体心脏功能的良好指标。
