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 addit ional 2 hours. Using modified hoyden chambers, high levels of neutroph il chemotactic activity were detected (using a checkerboard analysis) in the Coronary sinus effluents obtained during cardiac arrest. The ac tivity tended to decline during reperfusion. Assay of myeloperoxidase (a marker for neutrophils) revealed an accumulation of large numbers o f 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 o f reperfusion. Light microscopy evaluation confirmed the presence of n eutrophils, not only in the ventricles, but also in a greater number i n the right and left atria. Electron microscopy study of these hearts revealed the presence of mild reversible changes, indicating good pres ervation of the hearts during arrest. Results of this study provide ev idence for an acute inflammatory reaction that takes place after cardi ac operations and suggest a role for myocardial tissues in the initiat ion of such a response through their release of neutrophil chemotactic factors.