title: Arrhythmia risk stratification in idiopathic dilated cardiomyopathy based on echocardiography and 12-lead, signal-averaged, and 24-hour holter electrocardiography.
abstract: BACKGROUND
  To date, considerable controversy exists regarding noninvasive arrhythmia risk stratification in idiopathic dilated cardiomyopathy (IDC). Methods and Results Between 1992 and 1997, 202 patients with IDC without a history of sustained ventricular tachycardia (VT) underwent echocardiography, signal-averaged electrocardiogram (ECG), and 24-hour Holter ECG in the absence of antiarrhythmic drugs. During 32 +/- 15 months of prospective follow-up, major arrhythmic events, including sustained VT, ventricular fibrillation, or sudden death, occurred in 32 (16%) of 202 patients. After adjusting for baseline medical therapy and antiarrhythmic therapy during follow-up, multivariate Cox regression analysis identified a left ventricular (LV) end-diastolic diameter >/=70 mm and nonsustained VT on Holter as the only independent arrhythmia risk predictors. The combination of an LV end-diastolic diameter >/=70 mm and nonsustained VT was associated with a 14. 3-fold risk for future arrhythmic events (95% confidence interval 2. 3-90). To further elucidate the prognostic value of LV ejection fraction, multivariate Cox analysis was repeated with ejection fraction forced to remain in the model. In the latter model, an ejection fraction </=30% combined with nonsustained VT on Holter was found to be a significant arrhythmia risk predictor with a relative risk of 14.6 (95% confidence interval 2.2-97).
  
  
  CONCLUSIONS
  The combination of an LV end-diastolic diameter >/=70 mm and nonsustained VT on Holter, and the combination of LV ejection fraction </=30% and nonsustained VT on Holter, identify a subgroup of patients with IDC with a 14-fold risk for subsequent arrhythmic events. These findings have important implications for the design of future studies evaluating the role of prophylactic defibrillator therapy in patients with IDC.
authors.affiliation: Department of Cardiology, Hospital of the Philipps-University of Marburg, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Grimm
authors.forename: C
authors.initials: C
authors.lastname: Glaveris
authors.forename: J
authors.initials: J
authors.lastname: Hoffmann
authors.forename: V
authors.initials: V
authors.lastname: Menz
authors.forename: H H
authors.initials: HH
authors.lastname: Müller
authors.forename: G
authors.initials: G
authors.lastname: Hufnagel
authors.forename: B
authors.initials: B
authors.lastname: Maisch
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis* / Q000401:mortality* / Q000503:physiopathology; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D004452:Echocardiography / Q000379:methods*; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011336:Probability; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D016019:Survival Analysis; D014693:Ventricular Fibrillation / Q000175:diagnosis* / Q000453:epidemiology*