title: Predictors of electrical storm recurrences in patients with implantable cardioverter-defibrillators.
abstract: OBJECTIVE
  To determine prevalence and predictors of electrical storm recurrences (ES-Rs) in patients with implantable cardioverter-defibrillators (ICDs) as electrical storms (ESs) represent serious clinical events carrying a high risk of mortality.
  
  
  RESULTS
  Single-centre study analysing data of consecutive patients receiving an ICD between 1993 and 2008. Electrical storm was defined as ≥ 3 separate ventricular tachyarrhythmic (VT/VF) episodes ≤ 24 h. Nine hundred and fifty-five patients [mean left ventricular ejection fraction (LVEF) 35.7 ± 15.6%] were prospectively followed for 54.2 ± 35.5 months. In 274 of 955 patients (28.7%), 2871 VT/VF episodes were observed. One hundred and fifty-three ES episodes occurred in 63 of 955 patients (6.6%). Thirty-two of 63 patients (50.8%) experienced ≥ 2 ES episodes. Twenty-six of 32 patients (81.2%) with ES-Rs experienced the second ES episode within 1 year after the initial event. Cox regression analysis identified an LVEF ≤ 30% (OR 2.2; 95% CI 1.021-4.856; P = 0.044) and a patient's age >65 years (OR 3.5; 95% CI 1.207-10.176; P = 0.021) to be predictive for ES-Rs. Patients with angiotensin-converting enzyme (ACE) inhibitor therapy were less likely to experience ES-Rs (OR 0.39; 95% CI 0.187-0.817; P = 0.013).
  
  
  CONCLUSIONS
  Electrical storm events are not rare in a 'real-world' patient population with ICDs (6.6% in 4.5 years). The risk for ES-Rs, especially within the first year after the initial event, is high. Left ventricular ejection fraction ≤ 30%, age >65 years, and a lack of ACE inhibitor therapy are independent predictors of ES-R.
authors.affiliation: Department of Medicine-Cardiology, University Medical Centre Mannheim, Theodor-Kutzer-Ufer 1-3, Mannheim, Germany. florian.streitner@umm.de
authors.forename: Florian
authors.initials: F
authors.lastname: Streitner
authors.forename: Juergen
authors.initials: J
authors.lastname: Kuschyk
authors.forename: Christian
authors.initials: C
authors.lastname: Veltmann
authors.forename: Eva
authors.initials: E
authors.lastname: Mahl
authors.forename: Claudia
authors.initials: C
authors.lastname: Dietrich
authors.forename: Rainer
authors.initials: R
authors.lastname: Schimpf
authors.forename: Christina
authors.initials: C
authors.lastname: Doesch
authors.forename: Ines
authors.initials: I
authors.lastname: Streitner
authors.forename: Christian
authors.initials: C
authors.lastname: Wolpert
authors.forename: Martin
authors.initials: M
authors.lastname: Borggrefe
mesh_terms: D000368:Aged; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D012008:Recurrence; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000401:mortality* / Q000628:therapy*; D014693:Ventricular Fibrillation / Q000401:mortality* / Q000628:therapy*