title: Adenosine induced chest pain--a comparison between intracoronary bolus injection and steady state infusion.
abstract: OBJECTIVE
  Adenosine may induce chest pain in at least two ways, either by direct stimulation of sensory afferents before actual ischaemia occurs or secondary to ischaemia. The aim was to study if the mechanism of pain induction may depend on the method of adenosine administration.
  
  
  METHODS
  Increasing doses of adenosine were given to seven male patients with ischaemic heart disease referred for coronary angiography: first as a bolus intracoronary injection (2.5-50 mumol), second as a 1 ml.min-1 steady state infusion (0.01-20 mumol.min-1) and third as an intravenous steady state infusion (0.076-0.76 mumol.kg-1 x min-1). Pain, rate-pressure product, coronary sinus blood flow, and ECG were monitored. Lactate was analysed in coronary sinus and arterial blood.
  
  
  RESULTS
  After intracoronary bolus injection there were no signs of myocardial ischaemia, whereas during intracoronary steady state infusion, and in spite of a lower, but definite, degree of pain, 5/7 patients showed myocardial lactate production and three patients showed ST depression. During the intravenous steady state infusion 6/6 patients showed ST depression.
  
  
  CONCLUSIONS
  These findings suggest that when using adenosine for studies on the mechanisms of chest pain in patients with ischaemic heart disease it is preferable to use an intracoronary bolus injection technique rather than a steady state infusion, as the risk of inducing ischaemia with the latter model cannot be ignored.
authors.affiliation: University Hospital, Uppsala, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Lagerqvist
authors.forename: C
authors.initials: C
authors.lastname: Sylvén
authors.forename: E
authors.initials: E
authors.lastname: Theodorsen
authors.forename: L
authors.initials: L
authors.lastname: Kaijser
authors.forename: G
authors.initials: G
authors.lastname: Helmius
authors.forename: A
authors.initials: A
authors.lastname: Waldenström
mesh_terms: D000241:Adenosine / Q000008:administration & dosage* / Q000009:adverse effects; D000787:Angina Pectoris / Q000000981:diagnostic imaging / Q000503:physiopathology; D002637:Chest Pain / Q000139:chemically induced*; D017023:Coronary Angiography; D003327:Coronary Disease / Q000139:chemically induced; D004562:Electrocardiography; D006321:Heart / Q000187:drug effects*; D006801:Humans; D007262:Infusions, Intravenous; D007267:Injections; D007773:Lactates / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D010147:Pain Measurement
chemical_list: D007773:Lactates; D000241:Adenosine