We certainly agree with Dr Held that dipyridamole-thallium myocardial imaging eventually may become a useful alternative in noninvasive cardiac assessment among patients scheduled for elective peripheral vascular reconstruction, particularly those in whom conventional stress methods are inappropriate because of such common considerations as extremity claudication or restrictive pulmonary disease. The valuable article by Boucher and others did not appear in our list of references essentially for two reasons. First, of course, it was published only a few months ago, long after our manuscript had been submitted to the editorial board of the Archives. In this age of instantaneous communication, one sometimes forgets that an article has to be read before it can be referenced.
Second, intravenous dipyridamole presently is restricted to investigational use in the United States, and, at least at the Cleveland Clinic, is limited to patients whose myocardial imaging must be verified by coronary angiography even if the