title: Intramyocardial troponin-T monitoring with microdialysis in coronary artery bypass surgery.
abstract: OBJECTIVE
  To investigate the time course of troponin-T release into the extracellular fluid of the myocardium and to distinguish between a rise in troponin-T due to implantation trauma and an increase due to cardiac arrest during coronary surgery.
  
  
  METHODS
  Microdialysis probes were implanted in the heart of seven patients soon after sternotomy. Troponin-T was measured in the microdialysates and in peripheral blood from 3 h before to 24 h after heart arrest.
  
  
  RESULTS
  The troponin-T concentration in the microdialysates increased immediately after probe implantation and decreased to baseline within 70 min. This early peak is interpreted to reflect a local trauma. Three hours after cross-clamp release, a second peak of microdialysate troponin-T was recorded; 50 times higher than in serum. Eight to 24 h later a third peak occurred in five patients. Serum troponin-T was below the detection level at the beginning of the operation but increased linearly during the first 3 h of reperfusion and remained at that level thereafter.
  
  
  CONCLUSIONS
  Microdialysis is a safe technique providing more information on myocardial metabolism during and after bypass surgery than can be obtained from peripheral blood. The release of troponin-T in response to cardiac arrest can be distinguished in time from the local tissue response to probe implantation.
authors.affiliation: IRCCS Policlinico San Matteo Hospital, University of Pavia, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Mantovani
authors.forename: Charles
authors.initials: C
authors.lastname: Kennergren
authors.forename: Eva
authors.initials: E
authors.lastname: Berglin
authors.forename: Remigio
authors.initials: R
authors.lastname: Moratti
authors.forename: Peter
authors.initials: P
authors.lastname: Lönnroth
authors.forename: Anders
authors.initials: A
authors.lastname: Hamberger
authors.forename: Mario
authors.initials: M
authors.lastname: Viganó
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002316:Cardiotonic Agents / Q000627:therapeutic use; D001026:Coronary Artery Bypass / Q000295:instrumentation; D004298:Dopamine / Q000627:therapeutic use; D004562:Electrocardiography; D006324:Heart Arrest, Induced / Q000295:instrumentation; D006801:Humans; D007558:Italy; D008297:Male; D017551:Microdialysis; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D013525:Surgical Instruments; D013997:Time Factors; D016896:Treatment Outcome; D020107:Troponin T / Q000097:blood* / Q000187:drug effects
chemical_list: D015415:Biomarkers; D002316:Cardiotonic Agents; D020107:Troponin T; D004298:Dopamine