Occult gastrointestinal bleeding due to acquired von Willebrand syndrome in a patient with hypertrophic obstructive cardiomyopathy.

A 69-year-old woman presented with a harsh systolic murmur and severe anemia. Echocardiography demonstrated hypertrophic obstructive cardiomyopathy with a peak pressure gradient of 154 mmHg. Endoscopic examinations disclosed an angiodysplasia and multiple diverticula in the colon, but no active bleeding was noted in these lesions. A selective defect of large multimers of von Willebrand factor was detected by electrophoresis. After collection of anemia and Ca antagonist therapy, left ventricular obstruction was relieved and cessation of the occult gastrointestinal bleeding was obtained. This is the first report whereby acquired type 2A von Willebrand syndrome was caused by hypertrophic obstructive cardiomyopathy.