Acute Pulmonary Embolism
Pulmonary emboli (PE) occur following dislodgment of a venous thrombus from the deep veins of the leg or the pelvic veins which travels into the pulmonary arterial circulation. In patients with acute PE, unexplained dyspnoea pleuritic chest pain and haemoptysis are classical symptoms. Symptoms of massive PE are severe dyspnoea, syncope and low cardiac output. Pulmonary angiography is the invasive gold standard for diagnosing PE and was previously used where a ventilation/perfusion scan was non-diagnostic. In contemporary practice, the diagnosis of PE is based on validated clinical criteria combined with selective testing in view of non-specific symptoms and signs. The overriding strategy in the treatment of PE is the reduction of thrombosis, i.e. both the development and propagation of venous thrombus and the fibrinolysis or break-up of established, embolized clot. Thrombolytic therapy is indicated in the treatment of massive PE or PE with echocardiographic right ventricular dysfunction.