All of the following are true regarding DVT except: March 2008

Ans. B: May lead to lung infarction Deep venous thrombosis (DVT) most commonly involves the deep veins of the leg or arm, often resulting in potentially life-threatening emboli to the lungs. Emboli travel from the lower limb large veins and vena cava, through the right hea and lodges into the pulmonary aeries. This may totally occlude perfusion to all or pa of one or both lungs (pulmonary emboli). Acute right hea obstruction may lead to sudden collapse and death. Lung infarction is rare as the lung has a dual blood supply (bronchial and pulmonary aeries) Factors have been identified as known risk factors for the development of venous thrombosis. The single most powerful risk marker remains a prior history of DVT with up to 25% of acute venous thrombosis occurring in such patients. However, recurrent thrombosis may actually be the result of primary hypercoagulable states. Deficiencies of protein C, protein S, or antithrombin III accounts for approximately 5-10% of all cases of deep venous thrombosis.