Biomaterial Database

Intraindividual variability in electrocardiograms. 2008

Bob J A Schijvenaars, and Gerard van Herpen, and Jan A Kors

Department of Medical Informatics, Erasmus University Medical Center, Rotterdam, The Netherlands.

The electrocardiogram (ECG) can be affected by intraindividual variations from various sources that may confuse the diagnosis of the underlying cardiac condition and impair the accuracy of ECG interpretation. Intraindividual variability is a hindrance in serial ECG analysis, where ECGs of the same individual, but taken at different times, are compared. Two sources of intraindividual variability can be distinguished as follows: variability related to the technical circumstances during ECG recording (technical sources) and nonpathologic biologic variability (biological sources). Among the technical sources, variation in electrode positioning between recordings is the most confusing. Of the biological sources, respiratory variations are effective at any time scale, but the most important are age and weight that work on prolonged time scales. Technical problems are best prevented by rigorously sticking to a standard acquisition protocol. Criteria can be adapted to changing circumstances (age, weight), and by computer modeling, it may be possible to correct the ECG diagnosis for some sources of intraindividual variability.

UI	MeSH Term	Description	Entries
D004562	Electrocardiography	Recording of the moment-to-moment electromotive forces of the HEART as projected onto various sites on the body's surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a CATHODE RAY TUBE DISPLAY.	12-Lead ECG,12-Lead EKG,12-Lead Electrocardiography,Cardiography,ECG,EKG,Electrocardiogram,Electrocardiograph,12 Lead ECG,12 Lead EKG,12 Lead Electrocardiography,12-Lead ECGs,12-Lead EKGs,12-Lead Electrocardiographies,Cardiographies,ECG, 12-Lead,EKG, 12-Lead,Electrocardiograms,Electrocardiographies, 12-Lead,Electrocardiographs,Electrocardiography, 12-Lead
D004566	Electrodes	Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum.	Anode,Anode Materials,Cathode,Cathode Materials,Anode Material,Anodes,Cathode Material,Cathodes,Electrode,Material, Anode,Material, Cathode
D004868	Equipment Failure	Failure of equipment to perform to standard. The failure may be due to defects or improper use.	Defects, Equipment,Device Failure,Failure, Equipment,Malfunction, Equipment,Medical Device Failure,Misuse, Equipment,Device Failure, Medical,Device Failures, Medical,Failure, Medical Device,Failures, Medical Device,Defect, Equipment,Device Failures,Equipment Defect,Equipment Defects,Equipment Failures,Equipment Malfunction,Equipment Malfunctions,Equipment Misuse,Equipment Misuses,Failure, Device,Failures, Device,Failures, Equipment,Malfunctions, Equipment,Misuses, Equipment
D012680	Sensitivity and Specificity	Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)	Specificity,Sensitivity,Specificity and Sensitivity
D015203	Reproducibility of Results	The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.	Reliability and Validity,Reliability of Result,Reproducibility Of Result,Reproducibility of Finding,Validity of Result,Validity of Results,Face Validity,Reliability (Epidemiology),Reliability of Results,Reproducibility of Findings,Test-Retest Reliability,Validity (Epidemiology),Finding Reproducibilities,Finding Reproducibility,Of Result, Reproducibility,Of Results, Reproducibility,Reliabilities, Test-Retest,Reliability, Test-Retest,Result Reliabilities,Result Reliability,Result Validities,Result Validity,Result, Reproducibility Of,Results, Reproducibility Of,Test Retest Reliability,Validity and Reliability,Validity, Face
D015588	Observer Variation	The failure by the observer to measure or identify a phenomenon accurately, which results in an error. Sources for this may be due to the observer's missing an abnormality, or to faulty technique resulting in incorrect test measurement, or to misinterpretation of the data. Two varieties are inter-observer variation (the amount observers vary from one another when reporting on the same material) and intra-observer variation (the amount one observer varies between observations when reporting more than once on the same material).	Bias, Observer,Interobserver Variation,Intraobserver Variation,Observer Bias,Inter-Observer Variability,Inter-Observer Variation,Interobserver Variability,Intra-Observer Variability,Intra-Observer Variation,Intraobserver Variability,Inter Observer Variability,Inter Observer Variation,Inter-Observer Variabilities,Inter-Observer Variations,Interobserver Variabilities,Interobserver Variations,Intra Observer Variability,Intra Observer Variation,Intra-Observer Variabilities,Intra-Observer Variations,Intraobserver Variabilities,Intraobserver Variations,Observer Variations,Variabilities, Inter-Observer,Variabilities, Interobserver,Variabilities, Intra-Observer,Variabilities, Intraobserver,Variability, Inter-Observer,Variability, Interobserver,Variability, Intra-Observer,Variability, Intraobserver,Variation, Inter-Observer,Variation, Interobserver,Variation, Intra-Observer,Variation, Intraobserver,Variation, Observer,Variations, Inter-Observer,Variations, Interobserver,Variations, Intra-Observer,Variations, Intraobserver,Variations, Observer
D016477	Artifacts	Any visible result of a procedure which is caused by the procedure itself and not by the entity being analyzed. Common examples include histological structures introduced by tissue processing, radiographic images of structures that are not naturally present in living tissue, and products of chemical reactions that occur during analysis.	Artefacts,Artefact,Artifact
D019544	Equipment Failure Analysis	The evaluation of incidents involving the loss of function of a device. These evaluations are used for a variety of purposes such as to determine the failure rates, the causes of failures, costs of failures, and the reliability and maintainability of devices.	Materials Failure Analysis,Prosthesis Failure Analysis,Analysis, Equipment Failure,Analysis, Materials Failure,Analysis, Prosthesis Failure,Analyses, Equipment Failure,Analyses, Materials Failure,Analyses, Prosthesis Failure,Equipment Failure Analyses,Failure Analyses, Equipment,Failure Analyses, Materials,Failure Analyses, Prosthesis,Failure Analysis, Equipment,Failure Analysis, Materials,Failure Analysis, Prosthesis,Materials Failure Analyses,Prosthesis Failure Analyses