P波电轴左偏的心电图分析

Analysis of electrocardiography with P axis left deviation

目的分析100例患者常规12导联心电图P波电轴左偏的原因,并探讨上述P波的起源。方法采取用力咳嗽或阿托品静注的方式兴奋受试者窦房结,测量和分析咳嗽前后体表心电图(部分用食道电极)P波电轴、Ⅱ导联P波(PⅡ)形态及振幅的变化。结果100例P波电轴左偏,PⅡ形态异常,PⅡ振幅<0.05mV的患者中有85例在咳嗽后P波电轴和PⅡ形态、振幅随心率的增加发生显著变化,P波电轴由咳嗽前的-28.62±14.25变为+42.21±35.08,PⅡ形态由矮小、平坦、倒置变为直立,PⅡ振幅≥0.05mV。100例对照组患者的P波电轴为52.86±15.04,PⅡ直立,aVR倒置,PⅡ振幅≥0.05mV,咳嗽前后无明显变化。结论当P波电轴左偏在-1°～-60°之间时,P波时限<0.11s,PR间期>0.12s,PⅡ形态矮小、平坦、倒置,PⅡ、V5、V6直立,aVR倒置时,应考虑为右房房性心律。

Objective To analyze the cause of left deviation of P axis and the origin of the ectopic P wave using routine 12-leads Electrocardiogram. Methods The rate, axis and morphous of P waves of all subjects were recorded, measured and analyzed before and after intense coughing or Atropine IV., and statistic analysis was undertaken on the data we got above. Results The 100 patients with left deviation of P axis and voltage of PⅡ〈0.05mV, 85 underwent significantly changes in the P-axis and morphous of P, after coughing, which showed that P-axis changed from--28. 62±14.25° to ＋42.21 ± 35.08° and voltage of PⅡ ≥0.05mV. There were no significant P wave changes in the norreal control group before and after coughing. Conclusion Right atrial escape rhythm should be diagnosed when ECG showed P-axis ranged from-1° to-60°, P wave duration 〈0.11s, PR intervals 〉0.12s, voltage of P〈0.05mV, PH was flat, notched or inversed, Pn, Pv5-v6 was erect and P.w was flat or negative.