Evidence of cardiac inflammation after open heart operations

In this study, 6 anesthetized dogs underwent global cardiac arrest for 1 hour, followed by reperfusion on bypass for 45 minutes. The hearts were then weaned off cardiopulmonary bypass and monitored for an additional 2 hours. Using modified Boyden chambers, high levels of neutrophil chemotactic activity were detected (using a checkerboard analysis) in the coronary sinus effluents obtained during cardiac arrest. The activity tended to decline during reperfusion. Assay of myeloperoxidase (a marker for neutrophils) revealed an accumulation of large numbers of neutrophils in the right (14 +/- 1.1 x 10(4) cells/g wet weight) and left (16 +/- 1 x 10(4) cells/g wet weight) ventricles after 2 hours of reperfusion. Light microscopy evaluation confirmed the presence of neutrophils, not only in the ventricles, but also in a greater number in the right and left atria. Electron microscopy study of these hearts revealed the presence of mild reversible changes, indicating good preservation of the hearts during arrest. Results of this study provide evidence for an acute inflammatory reaction that takes place after cardiac operations and suggest a role for myocardial tissues in the initiation of such a response through their release of neutrophil chemotactic factors.