Endothelium-Dependent and -Independent Perfusion Reserve and the Effect of <scp>l</scp> -Arginine on Myocardial Perfusion in Patients With Syndrome X

To the Editor: We read the recent article by Bottcher et al1 with interest. Unfortunately, the authors do not discuss their findings in the light of a previous study by our group.2 This study is quite relevant to their work and was published in Circulation 5 years ago. In our experiment, we also used positron emission tomography to measure myocardial blood flow (MBF) at rest and after the administration of intravenous dipyridamole in patients with syndrome X (n=29) and in a substantial control group (n=20). Our principal finding was that no significant differences existed between patients and controls with respect to myocardial blood flow (Figure 1⇓). With a broader range of controls, Bottcher et al’s corresponding figure (Figure 2⇓) would probably not be distinguishable from ours. Although Bottcher et al’s data are quite consistent with ours in a number of respects, their interpretation of the data is perplexing. For example, on …