Clinical assessment of the effect of digital filtering on the detection of ventricular late potentials
Braz. j. med. biol. res
; 35(11): 1285-1292, Nov. 2002. tab, graf
Article
Dans En
| LILACS
| ID: lil-326259
Responsable en Bibliothèque :
BR1.1
ABSTRACT
Ventricular late potentials are low-amplitude signals originating from damaged myocardium and detected on the body surface by ECG filtering and averaging. Digital filters present in commercial equipment may interfere with the ability of arrhythmia stratification. We compared 40-Hz BiSpec (BI) and classical 40- to 250-Hz band-pass Butterworth bidirectional (BD) filters in terms of impact on time domain variables and diagnostic properties. In a transverse retrospective age-adjusted case-control study, 221 subjects with sinus rhythm without bundle branch block were divided into three groups after signal-averaged ECG acquisition GI (N = 40), clinically normal controls, GII (N = 158), subjects with coronary heart disease without sustained monomorphic ventricular tachycardia (SMVT), and GIII (N = 23), subjects with heart disease and documented SMVT. Conventional variables analyzed from vector magnitude data after averaging to 0.3 æV final noise were obtained by application of each filter to the averaged signal, and evaluated in pairs by numerical comparison and by diagnostic agreement assessment, using conventional and optimized thresholds of normality. Significant differences were found between BI and BD variables in all groups, with diagnostic results showing significant disagreement between both filters [kappa value of 0.61 (P<0.05) for GII and 0.31 for GIII (P = NS)]. Sensitivity for SMVT was lower with BI than with BD (65.2 vs 91.3 percent, respectively, P<0.05). Filters provided significantly different numerical and diagnostic results and the BI filter showed only limited clinical application to risk stratification of ventricular arrhythmia
Texte intégral:
1
Indice:
LILACS
Sujet Principal:
Troubles du rythme cardiaque
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Traitement du signal assisté par ordinateur
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Dysfonction ventriculaire
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Électrocardiographie
Type d'étude:
Diagnostic_studies
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Etiology_studies
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Evaluation_studies
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Incidence_studies
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Observational_studies
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Risk_factors_studies
Limites du sujet:
Female
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Humans
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Male
langue:
En
Texte intégral:
Braz. j. med. biol. res
Thème du journal:
BIOLOGIA
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MEDICINA
Année:
2002
Type:
Article
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Congress and conference
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Project document