Functional recovery of chronic ischemic myocardium after surgical revascularization correlates with magnitude of oxidative metabolism.
BACKGROUND
The purpose of this study was to validate myocardial microdialysis measurements in patients after myocardial infarction with or without associated postoperative functional recovery in order to develop a highly sensitive tool for real-time in vivo detection of microcellular disorder during cardiac operations.


METHODS
In 20 patients undergoing coronary artery bypass grafting, microdialysis catheters were implanted into scar or hibernating segments detected by means of magnetic resonance imaging, and into a vital area of the right ventricle (control). Myocardial glucose, lactate and pyruvate were analyzed perioperatively. Myocardial ethanol washout was measured as a sign of recovered local blood flow.


RESULTS
After surgical revascularization, improvement of wall motion was found in all hibernating segments compared to the scar segments paralleling an increased glucose delivery to the tissue and increased myocardial tissue flow. The myocardial glucose/lactate ratio and pyruvate also showed significantly higher values. Microdialytic measurements of the viable segments were comparable with those of the right ventricle.


CONCLUSIONS
Our results indicate that microdialysis measurements parallel magnetic resonance imaging findings in patients with revascularization of chronic ischemic myocardium with dyskinetic segments. The metabolism of those segments is characterized by a significantly increased tissue flow, an increased utilization of glucose and a better oxidative nutrition.
Pöling
Jochen
J
Department of Cardiac Surgery, Schuchtermann-Klinik, Bad Rothenfelde, Germany. jochen.poeling@freenet.de
Rees
Wolfgang
W
Klaus
Stephan
S
Bahlmann
Ludger
L
Hübner
Norbert
N
Heringlake
Matthias
M
Mantovani
Vittorio
V
Warnecke
Henning
H
D001026:Coronary Artery Bypass; D003326:Coronary Circulation; D000431:Ethanol; D005947:Glucose / Q000378:metabolism; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D017551:Microdialysis; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology / Q000601:surgery; D009206:Myocardium / Q000378:metabolism*; D019289:Pyruvic Acid / Q000378:metabolism; D020127:Recovery of Function; D013318:Stroke Volume; D016277:Ventricular Function, Left
D019344:Lactic Acid; D000431:Ethanol; D019289:Pyruvic Acid; D005947:Glucose