From the quantitative statistic comes the conclusion that standards for the normal cardio-vector is related with sex and age, QRS-T angle and S plane of NLS formed by V_1 and V_2 planes suggests the difference between sexes and between ages.

• 从定量统计结果推论正常心电向量标准应考虑性别、年龄的因素; 标准导联S面、V_1,V_2面的QRS-T角集中反映了性别、年龄间的差异,因此临床诊断时应考虑QRS-T角的演变规律。