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Educators

Hereditary and Acquired Thrombotic Disorders: Learning Objectives

Medical Importance

A substantial portion of patients with recurrent arterial or venous thrombosis are now known to have a hereditary or acquired defect that promotes thrombosis. Identification of many of these defects can rapidly be accomplished by the use of laboratory assays. The rationale for identifying these abnormalities is that patients can be protected during periods of thrombotic stress (for example, use of prophylactic anticoagulants in the perioperative period), a search can be made for family members who are affected with the abnormality, and specific therapies are now becoming available (for example, antithrombin concentrates for replacement in patients with antithrombin deficiency).

Objectives

  1. Identify the components of Virchow's triad and their pathophysiologic contribution to thrombosis.
  2. Be able to describe at least three major clinical symptoms that occur when a patient suffers from an acute iliofemoral thrombosis of the leg, and indicate the pathophysiologic reason for each one (for example, dilated superficial veins of the calf due to obstruction of venous return in the occluded deep veins).
  3. Be able to compare and contrast the cause and mechanism of a thrombus occurring in the arterial circulation (such as acute coronary artery thrombosis) from one that develops in a deep vein of the leg. Include the instigating factor(s) and composition of the clot.
  4. Be able to list 3 clinical clues suggesting an inherited hypercoagulable disorder.
  5. Be able to briefly describe (in one paragraph) at the molecular level the pathophysiologic reason that patients with deficiencies of antithrombin, protein C, or protein S, factor V Leiden or the prothrombin gene mutation are likely to have thrombosis. Explain what tests are used to identify these patients.
  6. Be able to list at least three acquired disorders that are associated with recurrent venous or arterial thromboembolism.
  7. Be able to describe the clinical features and criteria for diagnosis of antiphospholipid antibody syndrome.
  8. What is the KEY factor in determining how long someone should be anticoagulated for a venous thrombosis?