title: Effect of intravenous dipyridamole on coronary flow parameters in patients with isolated coronary artery ectasia: assessment by transesophageal echocardiography.
abstract: BACKGROUND
  In a prospective study design, we sought to assess the effect of dipyridamole on coronary flow parameters in patients with isolated coronary artery ectasia (CAE) as compared to subjects with normal coronaries.
  
  
  METHODS
  We enrolled 30 patients with ectasia of the left anterior descending (LAD) artery (study group), and 10 subjects with normal coronaries (control group). All subjects underwent transesophageal echocardiography to record flow velocities in the proximal LAD coronary artery, and velocity time integrals were calculated. The diameter of the proximal LAD coronary artery was measured and flow was calculated. Dipyridamole (0.56 mg/kg) was administered intravenously and measurements were repeated 5 minutes later.
  
  
  RESULTS
  At baseline, systolic and diastolic velocities, systolic, diastolic, and total velocity time integrals were significantly higher in the control group (P < 0.05 for all), yet, systolic, diastolic, and total coronary flow were significantly higher in the study group (P < 0.05 for all). Following dipyridamole administration, systolic, diastolic, and total coronary flow were still significantly higher in the study group (P < 0.05 for all), yet, there was no significant difference between the two groups regarding the other parameters, and regarding coronary reserve values (P > 0.05 for all).
  
  
  CONCLUSIONS
  We concluded that patients with isolated CAE have a higher resting coronary flow as compared to control subjects with normal coronaries. Intravenous dipyridamole administration in these patients maintained a significantly higher coronary flow, with a coronary flow reserve similar to controls.
authors.affiliation: Cardiology Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
authors.forename: Khaled
authors.initials: K
authors.lastname: Hossam
authors.forename: Tarek M K
authors.initials: TM
authors.lastname: Abdeldayem
authors.forename: Mohamed
authors.initials: M
authors.lastname: Gamal
authors.forename: Mohamed
authors.initials: M
authors.lastname: Ismail
authors.forename: Wail
authors.initials: W
authors.lastname: Nammas
authors.forename: M Khairy
authors.initials: MK
authors.lastname: Abdel-Dayem
mesh_terms: D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D003326:Coronary Circulation / Q000187:drug effects*; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging / Q000503:physiopathology; D004176:Dipyridamole / Q000008:administration & dosage; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D014665:Vasodilator Agents; D004176:Dipyridamole