Open AccessAgreement Between Automatic and Manual Measurement of Atrial and Ventricular Signal‐Averaged Electrocardiograms in Healthy Subjects
Author(s) -
Savelieva Irina,
Aytemir Kudret,
Hnatkova Katerina,
Camm A. John,
Malik Marek
Publication year - 2000
Publication title -
annals of noninvasive electrocardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.494
H-Index - 48
eISSN - 1542-474X
pISSN - 1082-720X
DOI - 10.1111/j.1542-474x.2000.tb00378.x
Subject(s) - medicine , signal averaged electrocardiogram , qrs complex , cardiology , electrocardiography , signal averaging , signal transfer function , digital signal processing , analog signal , electrical engineering , engineering
Background: Although prolonged duration of the signal‐averaged (SA) P wave has been proposed as a noninvasive marker of atrial arrhythmias, clinical value of atrial SAECG is limited, largely due to the difficulty with detection of the onset and offset of the high gain P wave. The aim of this study was to assess the reliability of automatic measurement of the atrial SAECG. Methods: Fifty‐one healthy volunteers (30 men; 32 ± 8 years) underwent a session of 3 atrial and 3 ventricular SAECG recordings. Automatically detected onset and offset of SA QRS complex (QRS tot ) and SA P wave (P tot ) were subsequently‐corrected by two independent observers. For ventricular SAECG, three conventional time‐domain parameters were calculated. For atrial SAECG, the following five parameters were measured: P tot , root mean square voltages of the entire P tot (RMS‐P) and of the terminal 40, 30, and 20 ms of P tot . Relative errors of the different pairs of measurements were used to assess the interobserver and observer‐computer variability. The Bland‐Altman method was applied to express the agreement between measurements. Results: Although the mean interobserver relative errors were low for QRS tot and P tot (1.1% vs 1.5%), the observer‐computer error was significantly higher for P tot than for QRS tot (1.7% vs 7.1%; P < 0.0001). For the voltage parameters, the lowest interobserver and observer‐computer relative errors were found for RMS‐P (6.6% vs 7.3%, P = ns). For RMS voltages of the terminal 40–20 ms of P tot , relative errors exceeded 10%, but the interobserver error was significantly lower than the observer‐computer error (P < 0.0001). Conclusion: Automatic detection of the SA P‐wave onset and offset is unreliable and the atrial SAECG requires manual correction. Given a good interobserver agreement, such a correction is unlikely to introduce any significant observer‐dependent bias. A.N.E. 2000; 5(2):133–138