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Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

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  • ECG:
    • often normal except for sinus tachycardia
    • atrial fibrillation is not uncommon
    • the classic S1,Q3,T3 with right axis deviation and right bundle branch block is uncommon
    • evidence of myocardial ischaemia
  • chest radiography occasionally show reduced vascular markings
  • blood gases show impaired gas exchange with arterial hypoxaemia and hypocapnia
  • pulmonary infarction causes an increased ESR
  • D-dimer - this is a highly sensitive but nonspecific test for diagnosing pulmonary embolism. A d-dimer below a certain cut point rules out PE with a high predictive value, at least in patients with a low or moderate clinical probability
  • ventilation-perfusion scan:
    • demonstrate areas of ventilation-perfusion mismatch
    • emboli are frequently multiple
    • the lower lobes are more frequently involved than the upper part of the lungs
  • CT pulmonary angiogram (CTPA) - generally performed for anybody with a clinically high risk for PE, or patients with low or moderate clinical risk and a positive D-dimer result. If a ventilation-perfusion scan is performed and the result is equivocal then CTPA should subsequently be performed
  • CT venography - a US review notes the combination of CTPA and CT venography increases the sensitivity of detection of pulmonary embolism (3)


  • there is study evidence that clevated troponin levels identify patients with acute pulmonary embolism at high risk of short-term death and adverse outcome events (4)
  • study evidence revealed that CTPA was not inferior to V/Q scanning in ruling out pulmonary embolism (5)
    • however, significantly more patients were diagnosed with pulmonary embolism using the CTPA approach
  • a review examined the diagnostic process for pulmonary embolism (3):
    • state of the art of diagnostic evaluation of hemodynamically stable patients with suspected acute pulmonary embolism was reviewed
      • diagnostic evaluation should begin with clinical assessment using a validated prediction rule in combination with measurement of D-dimer when appropriate
        • sensitivity for detection of pulmonary embolism was increased by combining CT angiography (4-slice or 16-slice) with CT venography
          • methods to reduce the radiation exposure of CT venography include imaging only the proximal leg veins (excluding the pelvis) and obtaining discontinuous images. Compression ultrasound can be used instead
          • in young women, radiation of the breasts produces the greatest risk of radiation-induced cancer. It may be that scintigraphy (V/Q scan) is the imaging test of choice in such patients
          • patient-specific approach to the diagnosis of pulmonary embolism can be taken safely in hemodynamically stable patients to increase efficiency and decrease cost and exposure to radiation


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