title: Analysis of the arrhythmogenic substrate in human heart failure.
abstract: BACKGROUND
  The mechanism of sudden cardiac death in patients with heart failure (HF) is uncertain. Both electrical instability and structural remodelling could be factors that lead to fatal arrhythmias. We sought to analyse the expression of the sodium (SCN5A) and potassium (KCND3) channels as well as the fibrosis content in the ventricles of human HF and of non-diseased hearts under different post-mortem intervals.
  
  
  RESULTS
  We analysed normal human hearts as controls [n=20 for the right ventricle (RV) and n=13 for the left ventricle (LV)] and human hearts from HF patients, which were obtained at the time of cardiac transplantation, as cases (n=48 for RV and n=34 for LV). Transcription of the SCN5A (probes SCN5A E4-5, E11-12, and E28) and KCND3 channels and of COLLAGEN I and III were assayed by real-time polymerase chain reaction. In addition, paraffin sections were used to analyse the percentage of collagen deposition in both cases and controls. KCND3 mRNA expression in the LV was lower in the cases than in controls (P<.001). Higher levels of SCN5A mRNA were found in the HF samples when analysed with probe SCN5A E4-5 (P<.05). SCN5A expression was lower in the controls with longer post-mortem interval (n=4) than in the controls with a shorter post- mortem interval (n=16, P<.01). KCND3 mRNA levels were also different between the two control groups (P<.05). Collagen deposition was higher in the LV tissues of the cases when compared to controls (P<.001), and it was higher in the LV from HF patients than in the RV (P<.05). Furthermore, collagen deposition was higher in the LV samples from patients with implanted cardiac defibrillator (ICD) therapy than in the LV of patients with no ICD therapy (P<.05).
  
  
  CONCLUSIONS
  These data indicate that ionic and structural remodelling could be pathophysiological mechanisms of cardiac arrhythmias in HF patients.
authors.affiliation: Thorax Institute-Hospital Clínic, University of Barcelona (Cardiology Department) Institute of Biomedical Research August Pi iSunyer (IDIBAPS), Spain. spartemi@yahoo.it
authors.forename: Sara
authors.initials: S
authors.lastname: Partemi
authors.forename: Montserrat
authors.initials: M
authors.lastname: Batlle
authors.forename: Paola
authors.initials: P
authors.lastname: Berne
authors.forename: Antonio
authors.initials: A
authors.lastname: Berruezo
authors.forename: Begoña
authors.initials: B
authors.lastname: Campos
authors.forename: Luis
authors.initials: L
authors.lastname: Mont
authors.forename: Helena
authors.initials: H
authors.lastname: Riuró
authors.forename: Eulalia
authors.initials: E
authors.lastname: Roig
authors.forename: Felix
authors.initials: F
authors.lastname: Pérez-Villa
authors.forename: Jose
authors.initials: J
authors.lastname: Ortiz
authors.forename: Vincenzo L
authors.initials: VL
authors.lastname: Pascali
authors.forename: Antonio
authors.initials: A
authors.lastname: Oliva
authors.forename: Ramon
authors.initials: R
authors.lastname: Brugada
authors.forename: Josep
authors.initials: J
authors.lastname: Brugada
mesh_terms: D000328:Adult; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000235:genetics / Q000378:metabolism*; D016022:Case-Control Studies; D003094:Collagen / Q000235:genetics / Q000378:metabolism; D016757:Death, Sudden, Cardiac / Q000209:etiology; D017147:Defibrillators, Implantable; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000235:genetics / Q000378:metabolism*; D006352:Heart Ventricles / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D062554:NAV1.5 Voltage-Gated Sodium Channel / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012307:Risk Factors; D051672:Shal Potassium Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: C497021:KCND3 protein, human; D062554:NAV1.5 Voltage-Gated Sodium Channel; D012333:RNA, Messenger; C568320:SCN5A protein, human; D051672:Shal Potassium Channels; D003094:Collagen