title: Factors underlying elevated troponin I levels following pacemaker primo-implantation.
abstract: BACKGROUND
  Cardiac troponins are routinely used as markers of myocardial damage. Originally, they were only intended for use in diagnosing acute coronary syndromes; however, we now know that raised serum troponin levels are not always caused by ischemia. There are many other clinical conditions that cause damage to cardiomyocytes, leading to raised levels of troponin. However, the specificity of cardiac troponins towards the myocardium is absolute. Our work focuses on mechanical damage to the myocardium and on monitoring the factors that raise the levels of cardiospecific markers after primo-implantation of a pacemaker with an actively fixed electrode.
  
  
  OBJECTIVE
  (i) To determine whether the use of a primo-implanted pacemaker with an electrode system with active fixation will raise troponin levels over baseline. (ii) To assess whether troponin I elevation is dependent on procedure complexity.
  
  
  METHODS
  We enrolled 219 consecutive patients indicated for pacemaker primo-implantation; cardiospecific marker values (troponin I, CKMB, myoglobin) were determined before the implantation procedure and again at 6- and 18-h intervals after the procedure. We monitored duration of cardiac skiascopy, number of attempts to place the electrode (active penetration into the tissue) and intervention range (single-chamber versus dual-chamber pacing), and we assessed the clinical data.
  
  
  RESULTS
  The average age of the enrolled patients was 78.2 ± 8.0 years (median age, 80 years); women constituted 45% of the group. We implanted 128 dual-chamber and 91 single-chamber devices with an average skiascopic time of 38.6 ± 22.0 s (median, 33.5 s). Troponin I serum levels increased from an initial 0.03 ± 0.07 μg/L (median, 0.01) to 0.18 ± 0.17 μg/L (median, 0.13) and 0.09 ± 0.18 μg/L (median, 0.04) at 6 and 18 h, respectively. The differences were statistically significant (P < 0.001 or P < 0.001). We confirmed a correlation between troponin increase and duration of skiascopy (P < 0.001). We also demonstrated a correlation between increased troponin I and number of attempts to place a pacemaker electrode (penetration into the tissue) at 6 h (P < 0.001) post-implantation.
  
  
  CONCLUSIONS
  We detected slightly elevated troponin I levels in patients with primo-implanted pacemakers using electrodes with active fixation. We demonstrated a direct correlation between myocardial damage (number of electrode penetrations into the myocardium) and troponin I elevation, as well as between complexity (severity) of the implantation procedure (indicated by prolonged skiascopy) and raised troponin I. The described phenomenon demonstrates the loss of the diagnostic role of troponin I early after pacemaker primo-implantation in patients with concomitant chest pain.
authors.affiliation: Department of Internal Medicine - Cardiology, 1st Faculty of Medicine, Charles University in Prague and Military University Hospital, Prague, Czech Republic.|Department of Internal medicine I - Cardiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Czech Republic.
authors.forename: Tomas
authors.initials: T
authors.lastname: Hnatek
authors.affiliation: Department of Internal medicine I - Cardiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Czech Republic.
authors.forename: Milos
authors.initials: M
authors.lastname: Taborsky
authors.affiliation: Department of Internal Medicine - Cardiology, 1st Faculty of Medicine, Charles University in Prague and Military University Hospital, Prague, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Maly
authors.affiliation: Department of Internal Medicine - Cardiology, 1st Faculty of Medicine, Charles University in Prague and Military University Hospital, Prague, Czech Republic.
authors.forename: Libor
authors.initials: L
authors.lastname: Kamenik
authors.affiliation: Institute of Biostatistics and Analyses, Masaryk University, Brno, Czech Republic.
authors.forename: Simona
authors.initials: S
authors.lastname: Littnerova
authors.affiliation: Department of Internal Medicine - Cardiology, 1st Faculty of Medicine, Charles University in Prague and Military University Hospital, Prague, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Sedlon
authors.affiliation: Department of Internal Medicine - Cardiology, 1st Faculty of Medicine, Charles University in Prague and Military University Hospital, Prague, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Luxova
authors.affiliation: Department of Internal Medicine - Cardiology, 1st Faculty of Medicine, Charles University in Prague and Military University Hospital, Prague, Czech Republic.
authors.forename: Marta
authors.initials: M
authors.lastname: Fiserova
authors.affiliation: Department of Clinical Biochemistry, Military University Hospital, Prague, Czech Republic.
authors.forename: Lenka
authors.initials: L
authors.lastname: Pospisilova
authors.affiliation: Department of Internal Medicine - Cardiology, 1st Faculty of Medicine, Charles University in Prague and Military University Hospital, Prague, Czech Republic.
authors.forename: Sarka
authors.initials: S
authors.lastname: Hamouzova
authors.affiliation: Department of Internal Medicine - Cardiology, 1st Faculty of Medicine, Charles University in Prague and Military University Hospital, Prague, Czech Republic.
authors.forename: Josef
authors.initials: J
authors.lastname: Danek
authors.affiliation: Department of Internal Medicine - Cardiology, 1st Faculty of Medicine, Charles University in Prague and Military University Hospital, Prague, Czech Republic.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Zavoral
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000097:blood / Q000628:therapy*; D015415:Biomarkers / Q000378:metabolism; D052279:Creatine Kinase, MB Form / Q000378:metabolism; D004567:Electrodes, Implanted; D005260:Female; D006801:Humans; D008297:Male; D009211:Myoglobin / Q000378:metabolism; D010138:Pacemaker, Artificial; D011183:Postoperative Complications / Q000097:blood / Q000175:diagnosis; D019919:Prosthesis Implantation; D019210:Troponin I / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D009211:Myoglobin; D019210:Troponin I; D052279:Creatine Kinase, MB Form
keywords: cardiac pacing; myocardial damage; primo-implantation; troponin