Deep Vein Thrombosis and Pulmonary Embolism in Congenital Factor VII Deficiency

Abstract

HEREDITARY deficiency of factor VII was first described by Alexander et al. in 1951.¹ Factor VII is necessary for the conversion of prothrombin into thrombin in the presence of tissue thromboplastin, and its deficiency is characterized by a prolonged Quick prothrombin time but normal tests of the intrinsic clotting system.^{2 3 4} It was initially thought that therapeutic anticoagulation with warfarin in the prevention and control of extension of red stasis thrombi was dependent upon achieving a Quick prothrombin time of 20 per cent control. This could often be achieved with high doses of drug on the first day, followed by a . . .