Prajapat Laxman, Ariyarajah Vignendra, Frisella Mary E, Apiyasawat Sirin, Spodick David H
Department of Medicine, Saint Vincent Hospital, Worcester, MA, USA.
Ann Noninvasive Electrocardiol. 2007 Jul;12(3):210-5. doi: 10.1111/j.1542-474X.2007.00163.x.
While P-wave duration (P-dur) and dispersion (P-disp) could both reflect fractionated and inhomogeneous propagation of sinus cardiac impulses, and may therefore be associated with each other, a clear relationship has not been extensively studied. We studied these markers as well as the significance of P-wave terminal force in lead V1 (PTFV1) in relation to the P-wave axis (P-axis).
We appraised our previously studied sample of 500 consecutively numbered, otherwise unselected, electrocardiograms (ECGs) of outpatients from the University of Massachusetts, Worcester, Massachusetts, for the foregoing P-wave characteristics. P-disp, defined as the difference of the duration between the widest and narrowest P wave, and the greatest P-dur after a 12-lead ECG search, was measured manually to the nearest 10 ms. PTFV1 was considered positive when > or = 40 mm2 terminal deflection was present on biphasic P waves on lead V1. Normal P-axis was considered 0 degrees to +75 degrees by manually constructing the mean frontal plane electrical P-axis from standard limb leads.
After excluding those with atrial arrhythmias, paced rhythms, errors in lead placement, P waves with low amplitude or overall technically poor tracing, 428 ECGs formed our final sample. P-dur was strongly associated with P-disp (P < 0.0001), but the correlation remained weak (r = 0.42). Overall, P-dur was not significantly associated with P-axis but when divided into tertiles and quintiles, the significance was evident within the range of the normal P-axis, particularly 0 degrees to +60 degrees (P < 0.0001). In a subanalysis of 380 ECGs that had appreciable biphasic P waves on lead V1, PTFV1 was noted on 178 (47%) ECGs and was significantly associated with P-dur (P < 0.0001), P-disp (P < 0.0001), and P-axis (P = 002). When considering P-axis in tertiles and quintiles, P-dur was greater in patients with a positive PTFV1 and significant within the normal range of the P-axis, especially from 0 degrees to +60 degrees .
P-dur, P-disp, and PTFV1 appear to share a significant tripartite association in relation to the normal P-axis, particularly when P-axis ranges 0 degrees to +60 degrees . Therefore, for optimal clinical assessment, these markers should be evaluated in relation to the normal P-axis.
虽然P波时限（P-dur）和离散度（P-disp）都能反映窦性心脏冲动的碎裂和不均匀传导，因此可能相互关联，但尚未对它们之间的明确关系进行广泛研究。我们研究了这些指标以及V1导联P波终末电势（PTFV1）与P波电轴（P轴）的关系及意义。
我们评估了之前研究的来自马萨诸塞州伍斯特市马萨诸塞大学门诊患者的500份连续编号、未做其他选择的心电图（ECG），以分析上述P波特征。P-disp定义为12导联心电图检查后最宽与最窄P波时限之差，最宽P波时限手动测量至最接近的10毫秒。当V1导联双相P波终末偏移≥40mm²时，PTFV1被视为阳性。通过手动从标准肢体导联构建平均额面心电P轴，正常P轴范围被认为是0°至+75°。
排除房性心律失常、起搏心律、导联放置错误、低振幅P波或整体技术质量差的心电图后，428份心电图构成了我们的最终样本。P-dur与P-disp密切相关（P<0.0001），但相关性仍较弱（r=0.42）。总体而言，P-dur与P轴无显著相关性，但分为三分位数和五分位数时，在正常P轴范围内，尤其是0°至+60°时，相关性显著（P<0.0001）。在对380份V1导联有明显双相P波的心电图进行的亚分析中，178份（47%）心电图出现PTFV1，且与P-dur（P<0.0001）、P-disp（P<0.0001）和P轴（P=0.02）显著相关。当将P轴分为三分位数和五分位数时，PTFV1阳性患者的P-dur更大，且在P轴正常范围内具有显著性，尤其是0°至+60°时。
P-dur、P-disp和PTFV1在与正常P轴的关系上似乎存在显著的三方关联，尤其是当P轴范围为0°至+60°时。因此，为了进行最佳的临床评估，应结合正常P轴对这些指标进行评估。
