BACKGROUND: Heyde syndrome is described as the association of arteriovenous 
malformations (AVMs) of the gastrointestinal tract and aortic stenosis (AS); its 
existence, however, has been questioned. We examined whether there is an 
association between AVMs and AS when objective measures are used to diagnose 
these findings.
METHODS: We identified all patients who were diagnosed with AVMs between 1990 
and 2000 by means of gastrointestinal endoscopy or mesenteric angiography. We 
compared the prevalence of AS and mitral stenosis (MS) in the 73 patients with 
AVMs who also had echocardiograms. For a comparison with the general population, 
the prevalence of AS and MS in all patients who had echocardiograms between 1990 
and 2000 was calculated (MS was chosen for comparison as a lesion with similar 
likelihood of prompting an echocardiographic evaluation).
RESULTS: The prevalence of AS was 31.7% in patients with AVMs, which was 
significantly higher than the 14.0% found in the general population comparison 
group (P<.001). The prevalence of MS was 1.6% in the AVM group, which was not 
statistically different from the 6.0% MS prevalence in the general 
echocardiogram population (P =.14). Significant AS was 2.6 times more common, 
and severe AS was 4.1 times more common, in patients with AVMs than in the 
general population. Age and sex were not associated with Heyde syndrome, but the 
association was more prevalent in blacks.
CONCLUSIONS: Our study confirmed an association between AVMs and AS, although 
the etiology of the Heyde syndrome remains unclear. Clinicians need to be aware 
of this syndrome because it may affect their management of patients with 
gastrointestinal bleeding or AS.