title: Ventricular repolarization dynamicity provides independent prognostic information toward major arrhythmic events in patients with idiopathic dilated cardiomyopathy.
abstract: OBJECTIVE
  The purpose of this work was to evaluate whether ventricular repolarization dynamicity predicts major arrhythmic events in patients with idiopathic dilated cardiomyopathy (DCM).
  
  
  BACKGROUND
  Arrhythmic risk stratification in patients with DCM is still an open issue. Ventricular repolarization analysis should provide relevant information, but QT interval and QT dispersion failed in predicting arrhythmic risk.
  
  
  METHODS
  The following parameters were evaluated in 179 consecutive DCM patients without history of sustained ventricular tachycardia (VT) and/or ventricular fibrillation (VF) at enrollment: QRS duration, QT interval corrected for heart rate, and QT dispersion at electrocardiogram (ECG); left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter at echocardiogram; and nonsustained ventricular tachycardia (NSVT), heart rate variability (standard deviation of RR intervals), and ventricular repolarization dynamicity as measured by means of 24-h ECG monitoring, by calculating the slope of linear regression analysis of QT end and RR intervals (QTe-slope) and the value of mean QT end corrected for heart rate.
  
  
  RESULTS
  During a mean follow-up of 39 months, 9 patients died suddenly and 15 experienced VT and/or VF. At multivariate analysis, LVEF (p = 0.047), NSVT (p = 0.022), and QTe-slope (p = 0.034) were significantly associated with arrhythmic events. Among the patients with a low LVEF, NSVT and/or steeper QTe-slope identified a subgroup at highest arrhythmic risk.
  
  
  CONCLUSIONS
  In patients with DCM, QT dynamicity is independently associated with the occurrence of major arrhythmic events and improves the predictive accuracy of stratifying arrhythmic risk of these patients.
authors.affiliation: Institute of Cardiology, University of Bari, Bari, Italy. massimo.iacoviello@cardio.uniba.it
authors.forename: Massimo
authors.initials: M
authors.lastname: Iacoviello
authors.forename: Cinzia
authors.initials: C
authors.lastname: Forleo
authors.forename: Pietro
authors.initials: P
authors.lastname: Guida
authors.forename: Roberta
authors.initials: R
authors.lastname: Romito
authors.forename: Antonio
authors.initials: A
authors.lastname: Sorgente
authors.forename: Sandro
authors.initials: S
authors.lastname: Sorrentino
authors.forename: Silvana
authors.initials: S
authors.lastname: Catucci
authors.forename: Filippo
authors.initials: F
authors.lastname: Mastropasqua
authors.forename: Mariavittoria
authors.initials: M
authors.lastname: Pitzalis
mesh_terms: D000328:Adult; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis* / Q000401:mortality; D015331:Cohort Studies; D016757:Death, Sudden, Cardiac; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D005260:Female; D006801:Humans; D016014:Linear Models; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013318:Stroke Volume; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000401:mortality; D020257:Ventricular Remodeling / Q000502:physiology