Catheterization of cardiac lymph trunk for evaluation of myocardial TNFα production and myocardial cell damage during cardiac operations

Objectives

To test the hypothesis that the myocardium is a site of TNF-α production and that cardiac lymph is more sensitive than venous blood from the coronary sinus (CS) to investigate myocardial cell damage related to cardiac operations in an experimental model.

Methods

In 14 young pigs the efferent cardiac lymph trunk and CS were cannulated before conventional cardiopulmonary bypass (CPB): lymph and blood were collected for perioperative TNFα and troponin I (TnI) measurement.

Results

TNFα was in similar range in cardiac lymph and in CS before, during and after CPB. There was no significant myocardial TNFα production related to CPB. TnI concentrations were significantly higher in cardiac lymph than in CS during and after CPB. A significant elevation of TnI related to CPB occurred in both cardiac lymph and CS, lymphatic concentrations reaching 100 times venous ones.

Conclusion

Our results exclude the myocardium as a major source of TNF-α and indicate myocardial cell damage with loss of important contractile cell proteins during CPB.

The significantly higher TnI concentrations in cardiac lymph (draining the myocardial interstitium) than in CS imply that determinations of plasmatic concentrations of TnI in the CS leads to strong underestimation of myocardial cell damage related to cardiac operations.