title: The signal-averaged electrocardiogram and late potentials. A comparative analysis of commercial devices.
abstract: The authors used two separate protocols to compare four commercially available devices for recording of the signal-averaged electrocardiogram and "late potentials" to assess their degree of concordance in identifying abnormalities. In one protocol, studies were performed using each system. In 19% of recordings the results from one system were discordant in at least one numeric parameter. In the second protocol identical averaged data files were used to identify discordancies due solely to differences in analysis algorithms used for QRS offset determination by the various devices. This disclosed 23% discordant findings, mostly in the root mean square amplitude of the terminal 40-msec segment resulting from small differences in the estimate of QRS offset point. To improve concordance between commercial systems, there is an urgent need for adoption of a rigorously standardized algorithm for analysis of baseline noise and QRS offset.
authors.affiliation: Department of Medicine, State University of New York Health Science Center.
authors.forename: R
authors.initials: R
authors.lastname: Henkin
authors.forename: E B
authors.initials: EB
authors.lastname: Caref
authors.forename: G J
authors.initials: GJ
authors.lastname: Kelen
authors.forename: N
authors.initials: N
authors.lastname: el-Sherif
mesh_terms: D000200:Action Potentials; D000465:Algorithms; D000704:Analysis of Variance; D004562:Electrocardiography / Q000295:instrumentation*; D006321:Heart / Q000502:physiology / Q000503:physiopathology*; D006331:Heart Diseases / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D011897:Random Allocation; D012016:Reference Values; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D016276:Ventricular Function