Madias John E
Mount Sinai School of Medicine of the New York University, New York, New York, USA.
Am J Cardiol. 2004 Aug 15;94(4):474-8. doi: 10.1016/j.amjcard.2004.05.006.
The feasibility of recording the intracardiac electrocardiogram (IC-ECG) through a saline-filled central venous catheter has been demonstrated. The importance of identifying P waves for the accurate characterization of arrhythmias has long been emphasized. The "Lewis lead" has been occasionally employed when the standard electrocardiogram (SECG) fails to detect P waves. The objectives of this study were to compare the amplitude of P waves recorded by intracardiac and standard ECGs and the Lewis lead and to explore whether the latter has any advantages over either type of electrocardiography. The amplitudes of P wave (in millimeters) measured on SECG, the Lewis lead, and IC-ECG obtained through a saline-filled central venous catheter were compared; recordings were obtained through the intracardiac electrocardiographic distal, medial, and proximal ports of the central venous catheter in 28 patients who underwent 62 measurements. P waves were larger on the distal port of the IC-ECG than on the medial and proximal ports, on lead V(1), the lead with the tallest P wave on SECG, and the Lewis lead (all p = 0.0005). P waves were also larger on the medial port than on the proximal port of the IC-ECG (p = 0.0005). P waves were larger on the proximal port of the IC-ECG than on lead V(1), the lead with the tallest P wave on SECG, and the Lewis lead (p = 0.0005 for the 2 leads), and P waves were larger with the Lewis lead than on lead V(1) (p = 0.0005) but did not differ from the lead with the tallest P wave on a SECG (p = 0.124). Augmented P waves can be secured by employment of an intracardiac electrocardiographic lead; the Lewis lead has no advantages over the SECG for detecting P waves. These data are useful when the amplitude of P waves is an issue of concern in clinical practice and research.
通过充满盐水的中心静脉导管记录心内心电图（IC - ECG）的可行性已得到证实。长期以来，人们一直强调识别P波对于准确表征心律失常的重要性。当标准心电图（SECG）未能检测到P波时，偶尔会采用“Lewis导联”。本研究的目的是比较心内和标准心电图以及Lewis导联记录的P波幅度，并探讨后者相对于任何一种心电图检查是否具有优势。比较了在SECG、Lewis导联以及通过充满盐水的中心静脉导管获得的IC - ECG上测量的P波幅度（以毫米为单位）；在28例接受了62次测量的患者中，通过中心静脉导管的心内心电图远端、中间和近端端口进行记录。IC - ECG远端端口的P波大于中间和近端端口、V(1)导联（SECG上P波最高的导联）以及Lewis导联上的P波（所有p = 0.0005）。IC - ECG中间端口的P波也大于近端端口（p = 0.0005）。IC - ECG近端端口的P波大于V(1)导联、SECG上P波最高的导联以及Lewis导联（这两个导联的p = 0.0005），Lewis导联的P波大于V(1)导联（p = 0.0005），但与SECG上P波最高的导联无差异（p = 0.124）。使用心内心电图导联可确保P波增大；在检测P波方面，Lewis导联相对于SECG没有优势。当P波幅度在临床实践和研究中是一个值得关注的问题时，这些数据是有用的。
