Evaluation of myocardial cell damage in cardiac lymph during cardiopulmonary bypass

Introduction

Cardiac lymph is a medium which reflects the myocardial interstitial space. The purpose of our study was to evaluate the inflammatory response marker TNFα (tumor necrosis factor-α) and myocardial injury marker Troponin I during cardiopulmonary bypass (CPB) in cardiac lymph and to compare them with blood values taken from the coronary sinus (SC).

Methods

In 14 young pigs the efferent cardiac lymph trunk and the SC was cannulated before starting CPB. Concentration of TNFα and Troponin I were measured pre, during and post CPB.

Results

A significant release of TNFα in SC and cardiac lymph was not observed.

Troponin I values in SC-blood rose from 2 ± 1.1ng/ml (mean ± SEM) before aortic cross-clamping (AoX) to 9.1 ± 3.2 ng/ml at the end of CPB and peaked 2 hours post CBP at 28.1 ± 10.9 ng/ml (P < 0.03). Troponin I concentration in cardiac lymph rose from 352 ± 64 ng/ml before AoX and became significantly higher in the following hours with a maximum value at 6 hours post CPB (12638 ± 5321 ng/ml; P < 0.01). A significant correlation between the lymphatic and SC-blood concentrations was noted.

Conclusion

(1) a significant release of TNFα was not observed in our study. (2) The high concentrations of Troponin I in cardiac lymph indicate a myocardial cell damage during CPB which is strongly underestimate by Sinus Coronarius blood samples.