title: Low-dose dipyridamole infusion acutely increases exercise capacity in angina pectoris: a double-blind, placebo controlled crossover stress echocardiographic study.
abstract: OBJECTIVE
  The aim of this study was to assess whether endogenous accumulation of adenosine, induced by low-dose dipyridamole infusion, protects from exercise-induced ischemia.
  
  
  BACKGROUND
  Adenosine is a recognized mediator of ischemic preconditioning in experimental settings.
  
  
  METHODS
  Ten patients (all men: mean age 63.4 +/- 7.3 years) with chronic stable angina, angiographically assessed coronary artery disease (n = 7) or previous myocardial infarction (n = 3) and exercise-induced ischemia underwent on different days two exercise-stress echo tests after premedication with placebo or dipyridamole (15 mg in 30 min, stopped 5 min before testing) in a double-blind, placebo controlled, randomized crossover design.
  
  
  RESULTS
  In comparison with placebo, dipyridamole less frequently induced chest pain (20% vs. 100%, p = 0.001) and >0.1 mV ST segment depression (50% vs. 100%, p < 0.05). Wall motion abnormalities during exercise-stress test were less frequent (placebo = 100% vs. dipyridamole = 70%, p = ns) and significantly less severe (wall motion score index at peak stress: placebo = 1.55 +/- 0.17 vs. dipyridamole = 1.27 +/- 0.2, p < 0.01) following dipyridamole, which also determined an increase in exercise time up to echocardiographic positivity (placebo = 385.9 +/- 51.4 vs. dipyridamole = 594.4 +/- 156.9 s, p < 0.01).
  
  
  CONCLUSIONS
  Low-dose dipyridamole infusion increases exercise tolerance in chronic stable angina, possibly by endogenous adenosine accumulation acting on high affinity A1 myocardial receptors involved in preconditioning or positively modulating coronary flow through collaterals.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Perugia, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Tommasi
authors.forename: E
authors.initials: E
authors.lastname: Carluccio
authors.forename: M
authors.initials: M
authors.lastname: Bentivoglio
authors.forename: L
authors.initials: L
authors.lastname: Corea
authors.forename: E
authors.initials: E
authors.lastname: Picano
mesh_terms: D000241:Adenosine / Q000378:metabolism; D000368:Aged; D000787:Angina Pectoris / Q000188:drug therapy* / Q000503:physiopathology; D018592:Cross-Over Studies; D004176:Dipyridamole / Q000008:administration & dosage* / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005080:Exercise Test / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011292:Premedication; D018047:Receptors, Purinergic P1 / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D018047:Receptors, Purinergic P1; D014665:Vasodilator Agents; D004176:Dipyridamole; D000241:Adenosine