title: Is the coexistence of sustained ST-segment elevation and abnormal Q waves a risk factor for electrical storm in implanted cardioverter defibrillator patients with structural heart diseases?
abstract: OBJECTIVE
  The aim of this study was to determine whether or not the coexistence of sustained ST-segment elevation and abnormal Q waves (STe-Q) could be a risk factor for electrical storm (ES) in implanted cardioverter defibrillator (ICD) patients with structural heart diseases.
  
  
  RESULTS
  In all, 156 consecutive patients received ICD therapy for secondary prevention of sudden cardiac death and/or sustained ventricular tachyarrhythmias were included. Electrical storm was defined as ≥3 separate episodes of ventricular tachycardia (VT) and/or ventricular fibrillation (VF) terminated by ICD therapies within 24 h. During a mean follow-up of 1825 ± 1188 days, 42 (26.9%) patients experienced ES, of whom 12 had coronary artery disease, 15 had idiopathic dilated cardiomyopathy, 6 had hypertrophic cardiomyopathy, 4 had arrhythmogenic right ventricular cardiomyopathy, 4 had cardiac sarcoidosis, and 1 had valvular heart disease. Sustained ST-segment elevation and abnormal Q waves in ≥2 leads on the 12-lead electrocardiography was observed in 33 (21%) patients. On the Kaplan-Meier analysis, patients with STe-Q had a markedly higher risk of ES than those without STe-Q (P< 0.0001). The multivariate Cox proportional hazards regression model indicated that STe-Q and left ventricular ejection fraction (LVEF) (<30%) were independent risk factors associated with the recurrence of VT/VF (STe-Q: HR 1.962, 95% CI 1.24-3.12, P= 0.004; LVEF: HR 1.860, 95% CI 1.20-2.89, P= 0.006), and STe-Q was an independent risk factor associated with ES (HR 4.955, 95% CI 2.69-9.13, P< 0.0001).
  
  
  CONCLUSIONS
  Sustained ST-segment elevation and abnormal Q waves could be a risk factor of not only recurrent VT/VF but also ES in patients with structural heart diseases.
authors.affiliation: The First Department of Internal Medicine,  Niigata University School of Medicine, 1-754 Asahi-machi-dori, Niigata 951-8510,  Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Furushima
authors.forename: Masaomi
authors.initials: M
authors.lastname: Chinushi
authors.forename: Kenichi
authors.initials: K
authors.lastname: Iijima
authors.forename: Kanae
authors.initials: K
authors.lastname: Hasegawa
authors.forename: Akinori
authors.initials: A
authors.lastname: Sato
authors.forename: Daisuke
authors.initials: D
authors.lastname: Izumi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Yoshifusa
authors.initials: Y
authors.lastname: Aizawa
mesh_terms: D000368:Aged; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000000981:diagnostic imaging / Q000453:epidemiology; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000706:statistics & numerical data; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000453:epidemiology*; D017147:Defibrillators, Implantable / Q000009:adverse effects* / Q000706:statistics & numerical data; D004562:Electrocardiography / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000453:epidemiology / Q000628:therapy; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000453:epidemiology*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015635:Radionuclide Ventriculography; D012307:Risk Factors; D012507:Sarcoidosis / Q000453:epidemiology; D012804:Sick Sinus Syndrome / Q000453:epidemiology* / Q000628:therapy*; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology