title: Value of time- and frequency-domain analysis of signal-averaged electrocardiography for arrhythmia risk prediction in idiopathic dilated cardiomyopathy.
abstract: Signal-averaged electrocardiography (SAECG) was performed in 120 consecutive patients with idiopathic dilated cardiomyopathy (IDC), and in 60 healthy controls. Time-domain analysis of SAECGs revealed ventricular late potentials in 27 of 120 patients with IDC (23%) compared to 2 of 60 controls (3%; P < 0.05). Frequency-domain analysis of SAECGs showed ventricular late potentials in 9 of 120 patients with IDC (8%) compared to none of the 60 controls (0%, P < 0.05). During a prospective follow-up of 15 +/- 7 months, serious arrhythmic events, defined as sustained ventricular tachyarrhythmias or sudden death, occurred in 17 of 120 patients with IDC (14%). The sensitivity, specificity, and positive and negative predictive values of ventricular late potentials for serious arrhythmic events were 35%, 80%, 22%, and 88% for the time-domain analysis, and 18%, 94%, 33%, and 87% for the frequency-domain analysis of SAECG, respectively. Thus, neither the time-nor the frequency-domain analysis of SAECG appears to be useful for risk stratification in the setting of IDC in view of their low sensitivity and low positive predictive value for serious arrhythmic events during follow-up.
authors.affiliation: Department of Medicine, Hospital of the Philipps-University of Marburg, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Grimm
authors.forename: J
authors.initials: J
authors.lastname: Hoffmann
authors.forename: U
authors.initials: U
authors.lastname: Knop
authors.forename: J
authors.initials: J
authors.lastname: Winzenburg
authors.forename: V
authors.initials: V
authors.lastname: Menz
authors.forename: B
authors.initials: B
authors.lastname: Maisch
mesh_terms: D000200:Action Potentials; D000293:Adolescent; D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology*; D002311:Cardiomyopathy, Dilated / Q000150:complications*; D016757:Death, Sudden, Cardiac / Q000209:etiology; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D017180:Tachycardia, Ventricular / Q000209:etiology; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000209:etiology; D016276:Ventricular Function