健康人的年龄、性别、体位、体型、呼吸、心率、心室容量、心肌收缩力及自主神经张力等均为影响QRS波群的相关因素。在这些因素中,呼吸、心率、心室容量、心肌收缩力以及自主神经张力本身都存在昼夜节律变化,从而使QRS电轴、振幅存在一系列年龄趋势、昼夜节律,并受到心率、体位等因素的影响。在心电图分析诊断中,应当结合临床实际情况,并充分考虑以上影响因素。 Age, sex, body position, body shape, respiration, heart rate, ventricular volume, myocardial contractility and autonomic nervous tension of healthy people are all related factors that affect QRS complex. Among these factors, there are circadian rhythms of respiration, heart rate, ventricular volume, myocardial contractility and autonomic nervous tension itself, so that there are a series of age trends, circadian rhythms, and heart rate, body position and other factors influences. In the ECG diagnosis, should be combined with the actual clinical situation, and give full consideration to the above factors.