title: Detection of myocardial injury during transvenous implantation of automatic cardioverter-defibrillators.
abstract: OBJECTIVE
  The present study was designed to assess the extent of myocardial injury in patients undergoing transvenous implantation of an automatic implantable cardioverter-defibrillator (ICD) using cardiac troponin I (cTNI), which is a highly specific marker of structural cardiac injury.
  
  
  BACKGROUND
  During ICD implantation, repetitive induction and termination of ventricular fibrillation (VF) via endocardial direct current shocks is required to demonstrate the correct function of the device. Transthoracic electrical shocks can cause myocardial cell injury.
  
  
  METHODS
  Measurements of total creatine kinase (CK), CK-MB, myoglobin, cardiac troponin T (cTNT) and cTNI were obtained before and after ICD implantation in 49 consecutive patients. Blood samples were drawn before and 2, 4, 8, and 24 h after implantation.
  
  
  RESULTS
  Elevations of CK, CK-MB, myoglobin, cTNT and cTNI above cut-off level were found in 25%, 6%, 76%, 37% and 14% of patients, respectively, with peak cTNI concentrations ranging from 1.7 to 5.5 ng/ml. Cumulative defibrillation energy (DFE), mean DFE, cumulative VF time, number of shocks as well as prior myocardial infarction (MI) were found to be significantly related to a rise of cTNI. Mean DFE > or = 18 J and a recent MI were identified as strong risk factors for cTNI rise.
  
  
  CONCLUSIONS
  During transvenous ICD implantation myocardial injury as assessed by cTNI rise occurs in about 14% of the patients. Peak cTNI concentrations are only minimally elevated reflecting subtle myocardial cell damage. Patients with a recent MI and a mean DFE > or = 18 J seem to be prone to cTNI rise.
authors.affiliation: Department of Cardiology, University of Giessen, Germany.
authors.forename: T M
authors.initials: TM
authors.lastname: Hurst
authors.forename: M
authors.initials: M
authors.lastname: Hinrichs
authors.forename: C
authors.initials: C
authors.lastname: Breidenbach
authors.forename: N
authors.initials: N
authors.lastname: Katz
authors.forename: B
authors.initials: B
authors.lastname: Waldecker
mesh_terms: D015415:Biomarkers / Q000097:blood; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D003402:Creatine Kinase / Q000097:blood; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D005260:Female; D006335:Heart Injuries / Q000175:diagnosis / Q000209:etiology*; D006801:Humans; D007527:Isoenzymes; D008297:Male; D008875:Middle Aged; D009211:Myoglobin / Q000097:blood; D019210:Troponin I / Q000097:blood; D020107:Troponin T / Q000097:blood
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D009211:Myoglobin; D019210:Troponin I; D020107:Troponin T; D003402:Creatine Kinase