de Micheli A, Medrano G A
Departamento de Electrocardiografía y Vectocardiografía, Instituto Nacional de Cardiología Ignacio Chávez, México, D.F.
Arch Inst Cardiol Mex. 1989 Nov-Dec;59(6):619-27.
When a low right atrial rhythm is present, P waves are negative in the low leads, they are variable in a VR and positive in a VL and LI. The figure eighth PF loop is located in the first quadrant, the PH loop has a counterclockwise rotation, and the PS can rotate in either direction. In the presence of upper left atrial rhythms, P waves are positive in the low leads and negative in a VL and a VR. The PF and PH loops can be found in the third quadrant of both planes with a clockwise rotation. If the rhythm originates in low left atrial regions, negative P waves are recorded in left precordial leads and positive ones in a VR and a VL. The PF loop has counterclockwise rotation or its branches superimposed and is situated in the second quadrant; PH with clockwise rotation is registered in the third quadrant; PS with either counterclockwise or clockwise rotation develops above and slightly ahead of the E point. When a nodal rhythm exists, P waves are negative in the low leads. The P loops show a counterclockwise rotation or a figure eight morphology. In the absence of atrial enlargements, the PF loop can be recorded in the first quadrant and the PH in the first or the fourth quadrant.
当存在低位右房节律时，P波在低位导联为负向，在aVR导联多变，在aVL和Ⅰ导联为正向。“8”字形PF环位于第一象限，PH环逆时针旋转，PS可向任一方向旋转。存在左上房节律时，P波在低位导联为正向，在aVL和aVR导联为负向。PF环和PH环可在两个平面的第三象限被发现且呈顺时针旋转。如果节律起源于低位左房区域，左胸前导联记录到负向P波，在aVR和aVL导联记录到正向P波。PF环逆时针旋转或其分支重叠，位于第二象限；PH顺时针旋转记录于第三象限；PS逆时针或顺时针旋转出现在E点上方且略前方。当存在交界性节律时，P波在低位导联为负向。P环呈逆时针旋转或“8”字形形态。在无心房扩大时，PF环可记录于第一象限，PH环可记录于第一或第四象限。
