Microdialysis of blood from the cardiac venous outflow: A technique for monitoring myocardial ischemia

Objective-To evaluate the possibility of using microdialysis of blood from the great cardiac vein for detecting myocardial ischemia. Design-Microdialysis catheters were placed in the great cardiac vein and th e left atrium of pigs for analysis of lactate, glycerol, pyruvate and gluco se. Blood samples were drawn for measurement of aspartate aminotransferase, alanine aminotransferase, lactic dehydrogenase and myoglobin with the obje ctive of verifying myocardial damage. Ischemia was induced for 3 h. Results-Fifteen minutes after induction of ischemia a significant elevation of lactate to 917 +/- 223%; p < 0.001 in the great cardiac vein could be r egistered. No significant changes in lactate levels were detected in the le ft atrium. Changes in glycerol and pyruvate showed similar patterns, with a n increase to 722 +/- 297%; p < 0.001 and to 281 +/- 56%; p < 0.05, respect ively. The outflow of aspartate aminotransferase and myoglobine in the grea t cardiac vein increased significantly. Conclusion-Early detection of metabolic substances is possible through the assessment of metabolic substances using microdialysis in the great cardiac vein.