Department of Internal Medicine, University of Massachusetts Medical School, Worcester, MA 01604, USA.
Int J Chron Obstruct Pulmon Dis. 2013;8:41-4. doi: 10.2147/COPD.S37776. Epub 2013 Jan 19.
Pulmonary emphysema of any etiology has been shown to be strongly and quasidiagnostically associated with a vertical frontal P wave axis. A vertical P wave axis (>60 degrees) during sinus rhythm can be easily determined by a P wave in lead III greater than the P wave in lead I (bipolar lead set) or a dominantly negative P wave in aVL (unipolar lead set). The purpose of this investigation was to determine which set of limb leads may be better for identifying the vertical P vector of emphysema in adults.
Unselected consecutive electrocardiograms from 100 patients with a diagnosis of emphysema were analyzed to determine the P wave axis. Patients aged younger than 45 years, those not in sinus rhythm, and those with poor quality tracings were excluded. The electrocardiographic data were divided into three categories depending on the frontal P wave axis, ie, >60 degrees, 60 degrees, or <60 degrees, by each criterion (P amplitude lead III > lead I and a negative P wave in aVL).
Sixty-six percent of patients had a P wave axis > 60 degrees based on aVL, and 88% of patients had a P wave axis > 60 degrees based on the P wave in lead III being greater than in lead I.
A P wave in lead III greater than that in lead I is a more sensitive marker than a negative P wave in aVL for diagnosing emphysema and is recommended for rapid routine screening.
任何病因引起的肺气肿均与垂直正向 P 波轴强烈相关，具有准诊断意义。窦性心律时，P 波电轴 >60°可通过以下方法轻易确定：Ⅲ导联 P 波>Ⅰ导联（双极导联），或 aVL 导联呈主导性负向 P 波（单极导联）。本研究旨在明确哪种导联更有助于确定成人肺气肿的垂直 P 向量。
对 100 例肺气肿患者的常规心电图进行分析，以确定 P 波电轴。排除年龄<45 岁、非窦性心律及心电图质量差的患者。根据 P 波振幅Ⅲ导联>Ⅰ导联和 aVL 导联呈负向 P 波（每个标准），将心电图数据分为 3 类，即 P 波电轴>60°、60°或<60°。
根据 aVL 导联，66%的患者 P 波电轴>60°，根据Ⅲ导联 P 波>Ⅰ导联，88%的患者 P 波电轴>60°。
与 aVL 导联负向 P 波相比，Ⅲ导联 P 波>I 导联更有助于诊断肺气肿，推荐用于快速常规筛查。
