Abstract: Hypertrophic cardiomyopathy (HCM) and aortic stenosis (AS) are common causes of left ventricular outflow tract (LVOT) obstruction. Hemodynamic changes in HCM or AS cause shear-induced destruction of high molecular weight von Willebrand factor, which leads to acquired von Willebrand factor syndrome (AvWS). This in turn increases risk of gastrointestinal hemorrhage, with or without secondary angiodysplasia. Treatment like aortic valve replacement, septal myectomy or alcohol septal ablation are ideal for patients with LVOT obstruction associated GI hemorrhage. Timely diagnosis and proper treatment relies on a thorough understanding of epidemiology and pathogeneesis of these patients.

Key words: Hypertrophic cardiomyopathy, angiodysplasia, gastrointestinal hemorrhage, acquired von Willebrand syndrome, Hyde syndrome