对８４例急性心肌梗塞（ＡＭＩ）心电向量图（ＶＣＧ）Ｐ环进行分析。结果：ＡＭＩ患者，特别是梗塞范围较大者，Ｐ环可以发生一系列变化；ＶＣＧＨ面Ｐ环最大向量振幅及最大向后向量或（和）最大向左向量振幅增大，负值Ｐ向量角增大，Ｐ环运行时间增加，Ｐ环运转方向也可以发生改变。上述Ｐ环变化是因为ＡＭＩ时心脏泵血功能骤减引起相应的左心房扩张造成的心房电学变化。提示：急性心肌梗塞Ｐ环异常与左心早期功能不全有关。 84 cases of acute myocardial infarction (AMI) ECG vector chart (VCG) P ring analysis. Results: In the AMI patients, especially in the infarct area, there was a series of changes in the P-ring. The amplitudes of the largest vector and the largest backward vector or (and) Increase, P ring running time increases, P ring running direction can also be changed. The change in the P-ring is due to a sudden decrease in cardiac pump function at the time of AMI resulting in atrial electrical changes due to the corresponding left atrial dilatation. Tip: P-ring anomalies in acute myocardial infarction and left ventricular dysfunction related.