To the Editor.—I read with interest the article by Ross et al1 in the April 1989 issue of the Archives. I think that their point about the safety of operating on patients with cardiac contusion as opposed to those patients who have suffered myocardial infarction is a very important one in dealing with patients with multiple trauma, who certainly can undergo operation for other problems with appropriate cardiovascular monitoring. This is an especially significant consideration in view of the benefits of early operative fixation of multiple fractures.
However, I do have some concerns with the article. It is noted in their "Patients and Methods" section that they use elevation of the creatine kinase MB (CK-MB) fraction over 2.5% to constitute a positive diagnostic criterion for cardiac contusion. Ross et al also used abnormalities in the electrocardiogram, including arrhythmias, ectopy, conduction defects, and ischemic changes, for their other diagnostic