Valvular Heart Disease and Acquired Type 2A von Willebrand Syndrome: The "Hemostatic" Waring Blender Syndrome.

Abstract

Few have witnessed the so-called Waring blender syndrome. This hemolysis of red blood cells, sometimes lifethreatening, typically occurs in the setting of a dysfunctional prosthetic heart valve. 1 Biomedical engineering and surgical advances have largely reduced this syndrome to textbooks. Unlike this exceedingly rare syndrome, acquired type 2A von Willebrand syndrome is a relatively common and typically unrecognized life-threatening condition with a similar etiology. 2 Acquired type 2A von Willebrand syndrome also arises from blood flow exposed to abnormally increased shear stress. Blackshear and colleagues 3 convincingly extend the recognition of acquired von Willebrand syndrome to dysfunctional prosthetic valves. They and others have previously described this phenomenon and confirmed its mechanism in native valve diseases, abnormal vascular structures, congenital heart lesions, and therapy with left ventricular assist devices. Advances in the last decade only now permit a detailed mechanistic understanding of this syndrome. While diagnostic and treatment criteria remain to be rigorously defined, pathophysiologic knowledge will help guide clinical recognition and management.