This letter is in response to the article by Batur et al, "Increased Prevalence of Aortic Stenosis in Patients With Arteriovenous Malformations of the Gastrointestinal Tract in Heyde Syndrome," that appeared in the August 11/25, 2003, issue.1 I would like to congratulate Drs Batur, Stewart, and Isaacson for showing a relationship between aortic stenosis and arteriovenous malformations (AVMs) of the gastrointestinal tract. The large number of patients in their retrospective review and their use of objective data from endoscopy, angiography, and echocardiography should make their conclusion convincing. However, I strongly object to describing it as the "Heyde syndrome." In a 1-paragraph Letter to the Editor in the New England Journal of Medicine in 1958, Heyde2 noted that he had seen 10 patients in the previous 10 years with calcific aortic stenosis who had gastrointestinal bleeding for which he could discover no cause. Nowhere did he describe the bleeding to be coming from an AVM. Galloway and associates3 were among the first to angiographically demonstrate vascular malformations in the right large bowel in patients who had aortic stenosis and lower intestinal bleeding of obscure cause. I was the first to perform colonoscopy in the Chicago area, so early in my career many patients were referred to me with obscure gastrointestinal bleeding. In a short time I had seen 5 patients who had an acquired vascular abnormality of the cecal area. I was able to control the bleeding by electrocoagulation in all 5 patients. None had "pure" aortic stenosis but all had cardiovascular disease.4 Baum and associates5 were instrumental in bringing this lesion to the attention of angiographers. Boley and associates6 did an injection study of resected colon specimens and found the vascular abnormalities quite frequent, even in apparently healthy patients. In my practice I accumulated more patients with bleeding vascular abnormalities of the gastrointestinal tract and published 27 of the cases in 1980.7 Twenty-four patients had the lesions in the colon and 3 in the stomach. Only 4 had aortic stenosis. Shortly after publishing this article I found typical bleeding vascular abnormalities in the jejunum at peroral enteroscopy in an elderly patient with advanced coronary artery disease. The problem with this syndrome is that it is not clear-cut. Not all patients with aortic stenosis develop an AVM lesion. Many incidental vascular abnormalities are found in the gastrointestinal tract not related to any other obvious diagnosis. My own theory is that acquired vascular abnormalities of the gastrointestinal tract are related to localized ischemia. It is generally accepted that ischemia induces the formation of angiogenesis factors. The lesions would have a predilection for the cecal area because that part of the anatomy is supplied by end arteries from the long superior mesenteric. In addition, the mucosa is exposed to the large volume of anaerobic content in the cecum, which acts as an oxygen sink. Localized ischemia can be caused by many factors, both local and ischemic. Thus, we have inconsistencies in the relationship between aortic stenosis and other conditions associated with acquired vascular abnormalities of the gastrointestinal tract.