Heyde's syndrome

Heyde's syndrome is a syndrome of gastrointestinal bleeding from angiodysplasia, a malformation of small blood vessels in the gut, in a person who also has aortic stenosis, a narrowing of the aortic valve. It is named after the American internist Edward C. Heyde, who described the association in 1958 in a letter reporting ten patients. The proposed mechanism is that blood forced at high speed through the narrowed valve exposes von Willebrand factor to high shear stress, so the factor unravels and is broken down by the enzyme ADAMTS13, producing acquired von Willebrand disease type 2A and a tendency to bleed from gut lesions. Diagnosis rests on confirming all three findings. Definitive treatment is replacement of the aortic valve, and transcatheter valve implantation has been proposed as an alternative. The syndrome is mainly seen in older adults and its exact prevalence is unknown.