title: Characteristics of ventricular fibrillation in relation to cardiac aetiology and shock success: A waveform analysis study in ICD-patients.
abstract: BACKGROUND
  Ventricular fibrillation (VF) waveform characteristics are associated with cardiac arrest duration and defibrillation success. Recent animal studies found that VF characteristics and shock success also depend on the presence of myocardial infarction (MI). In patients, VF induction after implantable cardioverter defibrillator (ICD) implantation offers a unique setting to study early VF characteristics: we studied the relation with cardiac disease--either presence or absence of a previous MI--and with shock success.
  
  
  METHODS
  Retrospective cohort study of ICD-patients who underwent defibrillation testing, 117 (63%) with and 69 (37%) without a previous MI. Intracardiac recordings of induced VF were analysed using Fourier analysis.
  
  
  RESULTS
  In previous MI-patients, the fundamental frequency and organisation index of the VF signal were significantly lower as compared with patients without a previous MI: 4.9 Hz ± 0.6 vs. 5.2 Hz ± 0.6 (p = 0.005) and 56% ± 10 vs. 60% ± 9 (p = 0.001), respectively. The median frequency was not different (p = 0.25). We found no association between VF characteristics and ICD shock success.
  
  
  CONCLUSIONS
  In analogy with observations in animals, we found that a history of a previous MI was associated with slower and less organised VF. In our cohort of ICD-patients, early VF waveform characteristics were not associated with shock outcomes. Further study is warranted to determine to what extent VF characteristics are influenced by the underlying aetiology on the one hand, and time delay on the other. These findings could improve insight into the potential value of VF analysis to guide shock delivery.
authors.affiliation: Department of Cardiology, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: judithbonnes@gmail.com.
authors.forename: Judith L
authors.initials: JL
authors.lastname: Bonnes
authors.affiliation: Department of Cardiology, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Wessel
authors.initials: W
authors.lastname: Keuper
authors.affiliation: Department of Cardiology, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Sjoerd W
authors.initials: SW
authors.lastname: Westra
authors.affiliation: Department of Cardiology, Canisius Wilhelmina Hospital, Weg door Jonkerbos 100, 6532 SZ Nijmegen, The Netherlands.
authors.forename: Erwin S
authors.initials: ES
authors.lastname: Zegers
authors.affiliation: Department of Cognitive Neuroscience, Donders Centre for Neuroscience, Radboud University Medical Centre, Kapittelweg 29, 6525 EN Nijmegen, The Netherlands.
authors.forename: Thom F
authors.initials: TF
authors.lastname: Oostendorp
authors.affiliation: Department of Cardiology, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Brouwer
authors.affiliation: Department of Cardiology, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Joep L R M
authors.initials: JL
authors.lastname: Smeets
mesh_terms: D015331:Cohort Studies; D017147:Defibrillators, Implantable; D004554:Electric Countershock; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications; D012074:Remission Induction; D012189:Retrospective Studies; D014693:Ventricular Fibrillation / Q000209:etiology / Q000503:physiopathology* / Q000628:therapy*
keywords: Defibrillation; Fourier analysis; Implantable cardioverter defibrillator; Ischemic heart disease; Ventricular fibrillation