title: The effect of precordial lead displacement on ECG morphology.
abstract: Inaccurate electrode placement and differences in inter-individual human anatomies can lead to misinterpretation of ECG examination. The aim of the study was to investigate the effect of precordial electrodes displacement on morphology of the ECG signal in a group of 60 patients with diagnosed cardiac disease. Shapes of ECG signals recorded from precordial leads were compared with signals interpolated at the points located at a distance up to 5 cm from lead location. Shape differences of the QRS and ST-T-U complexes were quantified using the distribution function method, correlation coefficient, root-mean-square error (RMSE), and normalized RMSE. The relative variability (RV) index was calculated to quantify inter-individual variability. ECG morphology changes were prominent in all shape parameters beyond 2 cm distance to precordial leads. Lead V2 was the most sensitive to displacement errors, followed by leads V3, V1, and V4, for which the direction of electrodes displacement plays a key role. No visible changes in ECG morphology were observed in leads V5 and V6, only scaling effect of signal amplitude. The RV ranged from 0.639 to 0.989. Distortions in ECG tracings increase with the distance from precordial lead, which are specific to chosen electrode, direction of displacement, and for ECG segment selected for calculations.
authors.affiliation: Department of Biophysical Measurements and Imaging, Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Trojdena 4, 02-109, Warsaw, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Kania
authors.forename: Hervé
authors.initials: H
authors.lastname: Rix
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Fereniec
authors.forename: Heriberto
authors.initials: H
authors.lastname: Zavala-Fernandez
authors.forename: Dariusz
authors.initials: D
authors.lastname: Janusek
authors.forename: Tomasz
authors.initials: T
authors.lastname: Mroczka
authors.forename: Günter
authors.initials: G
authors.lastname: Stix
authors.forename: Roman
authors.initials: R
authors.lastname: Maniewski
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004562:Electrocardiography / Q000379:methods*; D004566:Electrodes; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results