Heyde's syndrome

Heyde's syndrome is a syndrome of aortic valve stenosis associated with gastrointestinal bleeding from colonic angiodysplasia. It is named after Dr. Edward C. Heyde, who first described the association in 1958. It is due to the induction of von Willebrand disease type IIA by the valvular stenosis.

Signs and symptoms
Gastrointestinal hemorrhage may present as hematemesis (vomiting blood), melena (tarry stool from altered blood) or hematochezia (fresh blood in stool). These symptoms usually lead to endoscopy of the upper and/or lower digestive tract (gastroscopy or colonoscopy). If this shows angiodysplasia, and the patient is known to have aortic stenosis, the combination is referred to as "Heyde's syndrome". It is not necessary for the aortic stenosis to lead to any other symptoms, but evidence of heart failure, syncope or chest pain may be present if the stenosis is severe.

Diagnosis
The tests normally performed for Von Willebrand disease are not necessarily positive, as the abnormality is subtle. Platelet function analysis (with ADP closure time) or von Willebrand factor electrophoresis identifies reduction of ULVWF (ultra-large von Willebrand factor).

Pathophysiology
In the 45 years following its initial description, no plausible explanations could be found for the association between aortic valve stenosis and gastrointestinal bleeding. Indeed, the association itself was questioned by a number of researchers. A number of reports stressed, however, that replacement of the diseased aortic valve often led to resolution of the coagulopathy.

A 2003 study showed how the subtle form of von Willebrand disease present in Heyde syndrome patients resolved rapidly after aortic valve replacement of the stenosed aortic valve. The coagulation abnormality, the study poses, is possibly caused by the increased breakdown of the very large von Willebrand factor molecule by its natural catabolic enzyme (named ADAMTS13) under conditions of high shear stress around the valve.

Therapy
Symptomatic treatment can be given in the form of blood transfusions. Desmopressin (DDAVP) releases Factor VIII storage pools and is used in mild to moderate cases of von Willebrand disease.

Vincentelli et al. argue that severe forms of Heyde's syndrome might be sufficient reason for aortic valve replacement, even if the stenosis is otherwise clinically unimportant and is not likely to cause complications.

Epidemiology
The exact prevalence of the syndrome is unknown. A 2003 study found that of 73 angiodysplasia patients who had also undergone echocardiograms, the prevalence of aortic stenosis was 31% (as opposed to 14% in the control group).

History
The syndrome was originally described in 1958 by Dr Edward C. Heyde, an internist living and working in Vancouver, WA in a letter to the New England Journal of Medicine. He reported ten patients with the association. A letter appearing shortly after confirmed an odds ratio of almost 3.0 between the two diseases.