AaDO2 as a predictor of pulmonary hypertension resulting from pulmonary emboli

Cor Vasa. 1991;33(3):235-43.


The authors examined the records of all patients referred for right heart catheterization between 1963-84 because of persistent dyspnoea after one or more episodes of pulmonary emboli. Patients with a history of congestive heart failure, angina, restrictive or obstructive pulmonary disease that could explain their symptoms were excluded. Catheterization was performed 15.8 +/- 24 months after the first suspected episode of pulmonary embolism. Seven of the 29 patients included had resting pulmonary hypertension (PH). All of these had an alveolo-arterial oxygen difference (AaDO2) greater than 25 mmHg. Twenty patients of the group, taken as a whole, had an AaDO2 greater than 25 mmHg. Information was available from 1 month to 5 years later in 6/9 patients with an AaDO2 less than 25 mmHg. In all of them dyspnoea improved or resolved. Information was available in 15/20 patients with AaDO2 greater than 25 mmHg. Three of 8 patients without PH but with an increased AaDO2 on the initial catheterization developed PH within 2 years. Dyspnoea increased in 1 of the remaining five. Four patients who initially had PH developed right heart failure 6 months-3 years later. In the remaining 3, dyspnoea was stable in 1, increased in 1 and one patient died with autopsy evidence of multiple pulmonary emboli. Abnormal oxygenation predicts the presence or subsequent development of PH in patients who are chronically dyspnoeic after pulmonary embolism.

MeSH terms

  • Blood Pressure
  • Female
  • Humans
  • Hypertension, Pulmonary / blood
  • Hypertension, Pulmonary / etiology*
  • Hypertension, Pulmonary / physiopathology
  • Male
  • Middle Aged
  • Oxygen / blood
  • Oxygen Consumption
  • Pulmonary Embolism / complications*
  • Pulmonary Gas Exchange*
  • Pulmonary Wedge Pressure


  • Oxygen