title: Frequent asymptomatic pulmonary embolism in patients with deep venous thrombosis.
abstract: OBJECTIVE
  To determine the frequency of pulmonary embolism in patients admitted for treatment of deep venous thrombosis.
  
  
  METHODS
  An open, multicenter, dose-ranging study to assess the safety and pharmacokinetic characteristics of tissue-type plasminogen activator in deep venous thrombosis and pulmonary embolism. Perfusion and ventilation lung scans, chest roentgenograms, and venograms (in deep venous thrombosis) or pulmonary angiograms (in pulmonary embolism) were obtained before and 24 hours after inception of therapy. Heparin therapy was then administered.
  
  
  METHODS
  Five tertiary-care hospitals.
  
  
  METHODS
  All patients with suspected deep venous thrombosis or pulmonary embolism seen from August 1987 through November 1988 entered the study if they met inclusion criteria and if the diagnosis was confirmed by venogram (deep venous thrombosis) or pulmonary angiogram (pulmonary embolism).
  
  
  METHODS
  All patients received tissue-type plasminogen activator followed by intravenous heparin therapy.
  
  
  METHODS
  The primary measure was the frequency of pulmonary embolism in patients with deep venous thrombosis who had no symptoms of pulmonary embolism. This was not the original purpose of the study but emerged as an important finding as the data were analyzed.
  
  
  RESULTS
  Nearly 40% of patients with deep venous thrombosis who had no symptoms of pulmonary embolism had evidence of pulmonary embolism based on ventilation-perfusion scan and chest roentgenogram findings.
  
  
  CONCLUSIONS
  Because all of those considered to have embolism had so-called high-probability scan results, the frequency of embolism reported likely represents the minimum incidence of pulmonary embolism in patients with deep venous thrombosis who have no embolic symptoms. These data emphasize that venous thromboembolism is one disorder.
authors.affiliation: Department of Medicine, University of California, School of Medicine, San Diego.
authors.forename: K M
authors.initials: KM
authors.lastname: Moser
authors.forename: P F
authors.initials: PF
authors.lastname: Fedullo
authors.forename: J K
authors.initials: JK
authors.lastname: LitteJohn
authors.forename: R
authors.initials: R
authors.lastname: Crawford
mesh_terms: D000792:Angiography; D016903:Drug Monitoring; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D010690:Phlebography; D011655:Pulmonary Embolism / Q000150:complications* / Q000175:diagnosis*; D013902:Radiography, Thoracic; D011877:Radionuclide Imaging; D013924:Thrombophlebitis / Q000150:complications* / Q000000981:diagnostic imaging / Q000188:drug therapy; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*
chemical_list: D006493:Heparin; D010959:Tissue Plasminogen Activator