Dubin S, Beard R, Staib J, Hunt P
Am J Vet Res. 1977 Dec;38(12):1957-62.
The intraindividual variability in mean electric axis referable to choice of ECG leads and augmentation ratio was investigated by means of a digital computer program. Although, in theory, the choice of leads for determining the QRS axis should make no difference, the maximum intraindividual variation in axis angle was about 50 degrees for canine and feline subjects. The angle conputed for the lead combinations I and III and I and aVF will usually fall within 5 to 10 degrees of the mean of all lead combinations, but larger variations are seen at time. The application of an "augmentation ratio" for the augmented unipolar leads was most helpful when it was individually computed. Further methods of lead-vector improvement are discussed.
通过一个数字计算机程序研究了因心电图导联选择和增强比率导致的平均电轴个体内变异性。虽然理论上，用于确定QRS轴的导联选择不应产生差异，但犬类和猫科动物受试者的轴角最大个体内差异约为50度。导联组合I和III以及I和aVF计算出的角度通常会落在所有导联组合平均值的5至10度范围内，但有时也会出现较大差异。当单独计算时，对增强单极导联应用“增强比率”最为有用。还讨论了导联向量改进的进一步方法。
