右房上部的起搏点发出的激动,在右心房内传布的方向是由右后上向左前下,因此房性P环的方向不论是横面还是在额面上,均与窦性P环相似,由此投影所得的房性P波也与窦性P波的方向一致。而右房下部的起搏点发出的搏动,在心房内传布的方向是由右下指向左上,因此房性P环的方向不论是在 The apical part of the upper part of the pacemaker issued excitement, in the right atrium dissemination of the direction from the right back to the left before the next, so the direction of the atrial p-ring, whether horizontal or in the frontal plane, are sinusoidal ring Similarly, the projection of the atrial P wave is also consistent with the direction of the sinus P wave. The lower right atrial pacing pacemaker issued in the direction of the distribution of the heart is from the lower right corner pointing to the left, so the direction of the atrial p-ring, whether in the