The signal-averaged P wave duration: a rapid and noninvasive marker of risk of atrial fibrillation

Division of Cardiology, Columbia-Presbyterian Medical Center, New York, New York.

OBJECTIVES. This study was undertaken to determine the ability of the signal-averaged electrocardiogram (ECG) to identify evidence of delayed atrial activation in patients with a history of atrial fibrillation. BACKGROUND. Atrial fibrillation is a reentrant rhythm and depends on atrial conduction delay for its development. The signal-averaging technique is useful for accurately measuring total cardiac activation times, including delayed low amplitude signals, and thus can help identify the substrate for reentrant arrhythmias. METHODS. Standard 12-lead and signal-averaged ECGs were recorded from 15 patients with a documented history of prior paroxysmal or chronic atrial fibrillation and 15 age- and disease-matched control subjects without a history of atrial fibrillation. Signal averaging was performed using an orthogonal lead system with the QRS complex as a trigger and the P wave as a template for the signal-averaging process. Total P wave duration was measured before and after filtering with a least squares fit filter. The P wave complexes on the three bipolar leads were combined into a vector combination of orthogonal leads. The total P wave duration of the individual unfiltered and filtered leads and the vector combination of filtered leads were calculated and used for analysis. RESULTS. The P wave duration by standard ECG was not significantly different in patients with a history of atrial fibrillation and control subjects. Signal-averaged P wave durations were measured from orthogonal leads before and after digital filtering. Mean unfiltered P wave duration was significantly longer in patients with a history of atrial fibrillation than in control subjects (132 +/- 22 vs. 114 +/- 14 ms [p < 0.03] in the X lead, 135 +/- 21 vs. 115 +/- 15 ms [p < 0.03] in the Y lead and 133 +/- 23 vs. 114 +/- 14 ms [p < 0.03] in the Z lead). Mean filtered P wave duration was also longer in patients with atrial fibrillation than in control subjects (151 +/- 23 vs. 130 +/- 19 ms [p < 0.01] in the X lead, 157 +/- 22 vs. 136 +/- 17 ms [p < 0.01] in the Y lead and 154 +/- 23 vs. 135 +/- 15 ms [p < 0.01] in the Z lead). After filtering, a vector composite of orthogonal leads was determined. Again, P wave duration in patients with a history of atrial fibrillation exceeded that in the control subjects (162 +/- 15 vs. 140 +/- 12 ms [p < 0.01]). Using the vector composite of filtered orthogonal leads, a P wave duration > or = 155 ms was associated with a sensitivity of 80%, a specificity of 93% and a positive predictive value of 92% for identifying patients with history of atrial fibrillation. CONCLUSIONS. A prolonged signal-averaged P wave duration may be a simple noninvasive marker of the risk for development of atrial fibrillation.

This article has been cited by other articles:

				N-G Ilback, M Siller, and T Stalhandske Effects of buprenorphine on body temperature, locomotor activity and cardiovascular function when assessed by telemetric monitoring in rats Lab Anim, April 1, 2008; 42(2): 149 - 160. [Abstract] [Full Text] [PDF]

				C. Materazzo, P. Piotti, C. Mantovani, R. Miceli, and F. Villani Atrial fibrillation after non-cardiac surgery: P-wave characteristics and Holter monitoring in risk assessment Eur. J. Cardiothorac. Surg., May 1, 2007; 31(5): 812 - 816. [Abstract] [Full Text] [PDF]

				N. Hayashida, T. Shojima, Y. Yokokura, H. Hori, K. Yoshikawa, H. Tomoeda, and S. Aoyagi P-Wave Signal-Averaged Electrocardiogram for Predicting Atrial Arrhythmia After Cardiac Surgery Ann. Thorac. Surg., March 1, 2005; 79(3): 859 - 864. [Abstract] [Full Text] [PDF]

				G.Y.H. Lip and F.L. L. S. Hee Paroxysmal atrial fibrillation QJM, December 1, 2001; 94(12): 665 - 678. [Abstract] [Full Text] [PDF]

				V. Tuzcu, B. Ozkan, N. Sullivan, P. Karpawich, and M. L. Epstein P wave signal-averaged electrocardiogram as a new marker for atrial tachyarrhythmias in postoperative Fontan patients J. Am. Coll. Cardiol., August 1, 2000; 36(2): 602 - 607. [Abstract] [Full Text] [PDF]

				A. G. Zaman, R. A. Archbold, G. Helft, E. A. Paul, N. P. Curzen, and P. G. Mills Atrial Fibrillation After Coronary Artery Bypass Surgery : A Model for Preoperative Risk Stratification Circulation, March 28, 2000; 101(12): 1403 - 1408. [Abstract] [Full Text] [PDF]

				T. Yamada, M. Fukunami, T. Shimonagata, K. Kumagai, H. Ogita, Y. Asano, A. Hirata, M. Hori, and N. Hoki Prediction of paroxysmal atrial fibrillation in patients with congestive heart failure: a prospective study J. Am. Coll. Cardiol., February 1, 2000; 35(2): 405 - 413. [Abstract] [Full Text] [PDF]

				P.G. Platonov, J. Carlson, M.P. Ingemansson, A. Roijer, A. Hansson, L.V. Chireikin, and S.B. Olsson Detection of inter-atrial conduction defects with unfiltered signal-averaged P-wave ECG in patients with lone atrial fibrillation Europace, January 1, 2000; 2(1): 32 - 41. [Abstract] [PDF]

				T. Yamada, M. Fukunami, T. Shimonagata, K. Kumagai, S. Sanada, H. Ogita, Y. Asano, M. Hori, and N. Hoki Dispersion of signal-averaged P wave duration on precordial body surface in patients with paroxysmal atrial fibrillation Eur. Heart J., February 1, 1999; 20(3): 211 - 220. [Abstract] [PDF]

				T. Yoshida, H. Ikeda, T. Hiraki, I. Kubara, M. Ohga, and T. Imaizumi Detection of concealed left sided accessory atrioventricular pathway by P wave signal averaged electrocardiogram J. Am. Coll. Cardiol., January 1, 1999; 33(1): 55 - 62. [Abstract] [Full Text] [PDF]

				Y. Abe, M. Fukunami, T. Yamada, M. Ohmori, T. Shimonagata, K. Kumagai, J. Kim, S. Sanada, M. Hori, and N. Hoki Prediction of Transition to Chronic Atrial Fibrillation in Patients With Paroxysmal Atrial Fibrillation by Signal- Averaged Electrocardiography : A Prospective Study Circulation, October 21, 1997; 96(8): 2612 - 2616. [Abstract] [Full Text]