Systematic review of studies of the effect of hyperoxia on coronary blood flow

Am Heart J. 2009 Sep;158(3):371-7. doi: 10.1016/j.ahj.2009.05.037. Epub 2009 Jul 15.


Background: International guidelines recommend the routine use of oxygen in the initial treatment of myocardial infarction, yet it is uncertain what effect this might have on physiologic and clinical outcomes.

Methods: We undertook a systematic search of Medline, Cochrane Database of Systematic Reviews, EMBASE, and CINHAL using the key words "oxygen," "coronary blood flow," "hyperoxia," and "coronary circulation" to identify human studies involving a measure of coronary blood flow while breathing oxygen and room air. The primary outcome measure was coronary blood flow; secondary outcomes included coronary vascular resistance and myocardial oxygen consumption.

Results: From 2,072 potential publications, there were 6 studies from 4 publications that met the inclusion criteria, with 6 healthy subjects and 61 subjects with cardiac disease. It was not possible to undertake a meta-analysis due to methodological limitations. In the 6 studies, high-concentration oxygen therapy resulted in hyperoxia, with a range in mean Pao(2) of 273 to 425 mm Hg. Hyperoxia caused a significant reduction in coronary blood flow (mean change -7.9% to -28.9%, n = 6 studies). Hyperoxia caused a significant increase in coronary vascular resistance (mean change 21.5% to 40.9%, n = 4 studies) and a significant reduction in myocardial oxygen consumption (mean change -15.3% to -26.9%, n = 3 studies).

Conclusions: Hyperoxia from high-concentration oxygen therapy causes a marked reduction in coronary blood flow and myocardial oxygen consumption. These physiologic effects may have the potential to cause harm and are relevant to the use of high-concentration oxygen therapy in the treatment of cardiac and other disorders.

Publication types

  • Review
  • Systematic Review

MeSH terms

  • Coronary Circulation / physiology*
  • Heart / physiopathology*
  • Humans
  • Hyperoxia / physiopathology*
  • Myocardial Infarction / therapy*
  • Myocardium / metabolism
  • Oxygen Consumption / physiology
  • Oxygen Inhalation Therapy / adverse effects*
  • Vascular Resistance / physiology