摘要
正常心电图
明确判断一份心电图是否正常很重要，可根据下列特征进行判断（图1）。
P波
时限不超过110毫秒，波幅不超过0．25mV；前2／3由右心房除极产生，后1／3由左心房除极产生。健康人的P波在Ⅱ导联为直立向上，在V1导联为双向；前者向上的波要比后者向下的波大。
The normal, ECG It is important to confidently determine whether an ECG is normal, by the following features （Figure 1）.
P wave is 110 milliseconds or less and 0.25 mV or less; the first two-thirds are from right atrial depolarization, the last two-thirds from left atrial depolarization. In health, the P wave is upright in lead II and biphasic in lead V1; the first, positive deflection is larger than the second, negative one.
