Myocardial protection during bypass and arrest. A possible hazard with lactate-containing infusates

Severe myocardial tissue damage may results from the use of prolonged ischemic arrest during cardiac surgery. A number of experimental and clinical studies have been reported in which various protective agents have been infused into the coronary vessels before the onset of ischemia in an attempt to reduce or delay this damage. Although these agents are undoubtedly able to protect the ischemic myocardium, their efficacy may be considerably reduced or enhanced by the composition of the medium in which these agents are dissolved. In experiments with a rat heart model of bypass and ischemic arrest, we found that lactate-based media are detrimental to optimal tissue protection.