title: Cardiac troponin levels following implantable cardioverter defibrillation implantation and testing.
abstract: OBJECTIVE
  Previous studies have reported the defibrillation testing during implantable cardioverter defibrillator (ICD) implantation is associated with elevated cardiac biomarkers and ST-segment electrocardiogram (ECG) changes suggesting that shocks during testing may cause harm. However, the effects of testing have not been isolated from the implant procedure itself, where lead deployment may cause myocardial damage. This prospective study examined high sensitivity troponin T (hs-TnT) levels and ECG changes during ICD implanting alone, ICD implantation with testing and device testing as a stand-alone procedure.
  
  
  RESULTS
  We examined hs-TnT at baseline, and 6-8 h post procedure and 12 lead ECG at baseline, and 30 s, 5 min, and 10 min post right ventricle lead deployment and post defibrillation. There was no significant change in hs-TnT levels in a group of patients (n = 11) undergoing defibrillation testing alone, while hs-TnT was significantly elevated in patients undergoing implantation alone (n = 13, median increase 96%, P = 0.005) and in patients undergoing implantation and testing (n = 13, median increase 161%, P = 0.005). There was a significant correlation between the number of lead deployments and the percentage change in hs-TnT (r = -0.51, P = 0.01), but no correlation between either the number of shocks (r = 0.26, P = 0.25) or the total delivered energy (r = 0.24, P = 0.30) and percentage change in hs-TnT.
  
  
  CONCLUSIONS
  Implantation of ICD leads was associated with release of troponin, but we did not observe any evidence that ICD shocks alone cause myocardial injury.
authors.affiliation: Cardiology Department, Wellington Hospital, Wellington, New Zealand Wellington Cardiovascular Research Group, Wellington, New Zealand.
authors.forename: Guy
authors.initials: G
authors.lastname: Furniss
authors.affiliation: Wellington Cardiovascular Research Group, Wellington, New Zealand University of Otago Wellington, PO Box 7343, Wellington, New Zealand.
authors.forename: Bijia
authors.initials: B
authors.lastname: Shi
authors.affiliation: Cardiology Department, Wellington Hospital, Wellington, New Zealand Wellington Cardiovascular Research Group, Wellington, New Zealand.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Jimenez
authors.affiliation: Cardiology Department, Wellington Hospital, Wellington, New Zealand Wellington Cardiovascular Research Group, Wellington, New Zealand.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Harding
authors.affiliation: Wellington Cardiovascular Research Group, Wellington, New Zealand University of Otago Wellington, PO Box 7343, Wellington, New Zealand peter.larsen@otago.ac.nz.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Larsen
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood*; D011183:Postoperative Complications / Q000097:blood*; D011446:Prospective Studies; D019919:Prosthesis Implantation; D020107:Troponin T / Q000097:blood*
chemical_list: D020107:Troponin T
keywords: Defibrillation testing; High sensitivity cardiac troponin T; Implantable cardioverter defibrillator