Intramyocardial troponin-T monitoring with microdialysis in coronary artery bypass surgery.
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.
Mantovani
Vittorio
V
IRCCS Policlinico San Matteo Hospital, University of Pavia, Italy.
Kennergren
Charles
C
Berglin
Eva
E
Moratti
Remigio
R
Lönnroth
Peter
P
Hamberger
Anders
A
Viganó
Mario
M
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
D015415:Biomarkers; D002316:Cardiotonic Agents; D020107:Troponin T; D004298:Dopamine