title: Do induced tachycardias within the scope of electrophysiological studies lead to elevated plasma troponin I levels?
abstract: OBJECTIVE
  Troponin I (TNI) is an established marker for the diagnosis of acute coronary syndrome (ACS). The study evaluated if (induced) tachycardiac arrhyhthmias within the scope of the electrophysiological studies (EPS) led to elevation of TNI serum levels.
  
  
  METHODS
  TNI was measured in the serum of 28 patients before and after the EPS. The left ventricular ejection fraction (LV-EF) was investigated by two-dimensional echocardiography. Left ventricle hypertrophy (LVH) was measured according to the recommendations of the American Society of Echocardiography. All patients underwent coronary angiography prior to the EPS, and significant coronary heart disease was defined as stenosis > 50%. The EPS revealed supraventricular and ventricular tachycardias using the 18-step protocol with one, two, and three extrastimuli.
  
  
  RESULTS
  Indications for the EPS were syncope (n = 15), atrioventricular tachycardia (n = 4), non-sustained VT (n = 6), and sustained VT (n = 3). Coronary heart disease (CHD) was detected in 8 patients (1-vessel: n = 3; 2-vessel: n = 4; 3-vessel: n = 1), and 2 patients underwent percutaneous coronary intervention before EPS. Echocardiography revealed normal LV-EF in 18 patients and a reduction in the others (low n = 3, middle n = 5, high n = 2). Thirteen patients suffered from LVH. In 2 patients, external cardioversion was required during the EPS. TNI was elevated over 0.1 ng/ml (risk stratification cut-off for ACS) in 4 patients before and in 12 patients after EPS. There was no relationship between LV-EF, CHD, and the elevation of TNI after the EPS.
  
  
  CONCLUSIONS
  TNI can be elevated by (induced) tachycardias within the scope of electrophysiological studies without a relationship to LV-EF, LVH, and CHD.
authors: Medizinische Klinik 2, Universitätsklinikum Gießen, Klinikstr. 32, 35392, Gießen, Deutschland. dirk.bandorski@hkw.med.uni-giessen.de
authors: D
authors: D
authors: Bandorski
authors: H
authors: H
authors: Bogossian
authors: B
authors: B
authors: Lemke
authors: R
authors: R
authors: Höltgen
authors: M
authors: M
authors: Wieczorek
authors: M
authors: M
authors: Brück
mesh_terms: D015415:Biomarkers / Q000097:blood; D004562:Electrocardiography / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000097:blood* / Q000175:diagnosis*; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I