应用I，aVF直角坐标目测与计算判断心电轴

ESTIMATION OF ELEC0TRICAL AXIS BY INSPECTION AND CALCULATION IN THE USE OFI AND aVF PERPENDICULAR COORDINATE

用心电图的Ｉ与ａＶＦ导程构成的直角坐标，设计了分区分度分步分析目测与三角函数计算心电轴的方法。用该法测得９２份心电图与传统方法所测结果相符。该方法可供临床使用。

The I and aVF leadsin hexaxial system of ECG intersect 90°with each other and formaperpendicular coordinate, We used these two leads to analyse the electrical axis inspectionby steps: (1) distinguish the area with I and aVF,(2)differentiate the degree with Ⅱ aVRor Ⅲ aVL. The result of all 92 cases was the same as that of the traditional method. We also designed 4 formulas :adapted 0°～-90°(the first quadrant),0°～+90°(the second quadrant)+90°～+180°(the third quadrant),+l80～+270°(-180°～-90°the fourth quadrant)respectively. F=algebraic sum of QRS amplitude of lead aVF I=algebraic sum of QRS amplitude of lead I When the traditional method was compared with our calculation the difference was85.8%within±3°in 92 cases(P>0.05)We considered that electrical axis can be estimated by general inspection. Some caseswhich need accurate degrees can be computed by these formulas.