Demonstration of nonperfused myocardium in late hemorrhagic shock

Studies were performed to determine whether or not regions of left ventricle become nonperfused in the normovolemic stages of hemorrhagic shock. Using the endothelial fluorescent stain thioflavin S as a tracer, nonperfused myocardium was assessed in six control dogs, eight dogs in early normovolemic shock, and 15 dogs in late normovolemic shock. Nonperfused myocardium was not demonstrable in any of the control animals and in only one of the early shock animals. However, in nine of the late shock animals, nonperfused myocardium was clearly evident, particularly in the anterior and posterior papillary muscles. The demonstration of nonperfused myocardium in late shock is compatible with the concept of a progressively developing edema with a consequent interruption of blood flow.