Standa M, Iversen P O, Flatebø T, Nicolaysen G
Institute of Physiology, School of Medicine, Wroclaw, Poland.
J Physiol Pharmacol. 1992 Sep;43(3):209-18.
Several studies have reported an extensive regional heterogeneity in myocardial blood flow. The reported coefficients of variation for regional myocardial perfusion range from about 0.2 to 0.4 in normotensive animals. The spatial distribution of myocardial perfusion during haemorrhagic hypotension seems not to have been assessed. The goal of the present study was to determine the regional heterogeneity in myocardial blood flow within the rabbit left ventricle during normal conditions and after haemorrhagic hypotension. Radioactive microspheres were infused into the left ventricle in barbiturate anaesthetized rabbits over either 30 or 120 sec. The haemorrhagic hypotension was induced by bleeding, so that mean arterial blood pressure was reduced to about 50% of control. The left ventricles were divided into samples of about 0.025 g each. Regional heterogeneity in the blood flow was expressed as the coefficient of variation corrected for the Poisson distribution of microspheres (CVc). The CVc was 0.37 +/- 0.09 (mean +/- SD) during control and 0.41 +/- 0.11 after bleeding, the CVc obtained after bleeding being somewhat higher than during control (P < 0.05). We obtained a high correlation coefficient (tau about 0.68) between regional perfusion values at control and after bleeding which indicates a stable perfusion pattern within the myocardium. We conclude that the regional distribution of coronary blood flow within the left ventricle is markedly heterogenous during control condition and that this pattern is not changed during haemorrhagic hypotension.
多项研究报告了心肌血流存在广泛的区域异质性。在血压正常的动物中，所报道的局部心肌灌注变异系数范围约为0.2至0.4。出血性低血压期间心肌灌注的空间分布似乎尚未得到评估。本研究的目的是确定正常条件下和出血性低血压后兔左心室内心肌血流的区域异质性。在巴比妥酸盐麻醉的兔中，将放射性微球在30秒或120秒内注入左心室。通过放血诱导出血性低血压，使平均动脉血压降至对照值的约50%。将左心室分成每个约0.025 g的样本。血流的区域异质性表示为针对微球泊松分布校正的变异系数（CVc）。对照期间CVc为0.37±0.09（平均值±标准差），出血后为0.41±0.11，出血后获得的CVc略高于对照期间（P<0.05）。我们在对照和出血后的局部灌注值之间获得了较高的相关系数（τ约为0.68），这表明心肌内灌注模式稳定。我们得出结论，在对照条件下左心室内冠状动脉血流的区域分布明显不均匀，并且在出血性低血压期间这种模式没有改变。
