Department of Internal Medicine, University of Massachusetts Medical School, Plantation Street #813,Worcester, MA 01604, USA.
Int J Chron Obstruct Pulmon Dis. 2013;8:245-50. doi: 10.2147/COPD.S45127. Epub 2013 May 14.
Pulmonary emphysema causes several electrocardiogram changes, and one of the most common and well known is on the frontal P-wave axis. P-axis verticalization (P-axis > 60°) serves as a quasidiagnostic indicator of emphysema. The correlation of P-axis verticalization with the radiological severity of emphysema and severity of chronic obstructive lung function have been previously investigated and well described in the literature. However, the correlation of P-axis verticalization in emphysema with other P-indices like P-terminal force in V1 (Ptf), amplitude of initial positive component of P-waves in V1 (i-PV1), and interatrial block (IAB) have not been well studied. Our current study was undertaken to investigate the effects of emphysema on these P-wave indices in correlation with the verticalization of the P-vector.
Unselected, routinely recorded electrocardiograms of 170 hospitalized emphysema patients were studied. Significant Ptf (s-Ptf) was considered ≥40 mm.ms and was divided into two types based on the morphology of P-waves in V1: either a totally negative (-) P wave in V1 or a biphasic (+/-) P wave in V1.
s-Ptf correlated better with vertical P-vectors than nonvertical P-vectors (P = 0.03). s-Ptf also significantly correlated with IAB (P = 0.001); however, IAB and P-vector verticalization did not appear to have any significant correlation (P = 0.23). There was a very weak correlation between i-PV1 and frontal P-vector (r = 0.15; P = 0.047); however, no significant correlation was found between i-PV1 and P-amplitude in lead III (r = 0.07; P = 0.36).
We conclude that increased P-tf in emphysema may be due to downward right atrial position caused by right atrial displacement, and thus the common assumption that increased P-tf implies left atrial enlargement should be made with caution in patients with emphysema. Also, the lack of strong correlation between i-PV1 and P-amplitude in lead III or vertical P-vector may suggest the predominant role of downward right atrial distortion rather than right atrial enlargement in causing vertical P-vector in emphysema.
肺气肿可引起多种心电图改变，其中最常见和广为人知的是额面 P 波电轴改变。P 轴垂直化（P 轴＞60°）可作为肺气肿的半定性指标。P 轴垂直化与肺气肿的放射学严重程度和慢性阻塞性肺功能严重程度的相关性已在文献中得到充分研究。然而，肺气肿患者 P 轴垂直化与其他 P 波指标（如 V1 导联 P 波终末电势（Ptf）、V1 导联 P 波初始正向波振幅（i-PV1）和房间隔阻滞（IAB））之间的相关性尚未得到很好的研究。我们目前的研究旨在探讨肺气肿对这些 P 波指标的影响，并与 P 向量的垂直化相关。
对 170 例住院肺气肿患者的常规心电图进行了研究。显著 Ptf（s-Ptf）定义为≥40mm.ms，并根据 V1 导联 P 波形态分为两种类型：V1 导联完全负向（-）P 波或双向（+/–）P 波。
s-Ptf 与垂直 P 向量的相关性优于非垂直 P 向量（P=0.03）。s-Ptf 也与 IAB 显著相关（P=0.001）；然而，IAB 和 P 向量的垂直化似乎没有任何显著相关性（P=0.23）。i-PV1 与额面 P 向量有微弱相关性（r=0.15；P=0.047）；然而，i-PV1 与 III 导联 P 波振幅之间未发现显著相关性（r=0.07；P=0.36）。
我们得出结论，肺气肿中 s-Ptf 的增加可能是由于右心房位置下移导致右心房移位所致，因此在肺气肿患者中，应谨慎对待 s-Ptf 增加意味着左心房增大的常见假设。此外，i-PV1 与 III 导联 P 波振幅或垂直 P 向量之间缺乏强相关性可能表明，在肺气肿中导致 P 向量垂直化的主要因素是右心房向下扭曲，而不是右心房增大。
