title: Multislice CT coronary angiography: effect of sublingual nitroglycerine on the diameter of coronary arteries.
abstract: OBJECTIVE
  To investigate the influence of sublingual glycerol trinitrate (1.2 mg, Nitrate [nitroglycerine], Nitrolingual N Spray) on the coronary artery diameter on multislice computed tomography (MSCT) coronary angiography.
  
  
  METHODS
  Out of our database of patients who underwent MSCT (slice thickness of 0.5 mm, Aquilion, Toshiba) coronary angiography between July 2003 and November 2005 (950 patients) we retrospectively identified patients with follow-up examinations who received Nitrate for one examination while another examination was performed without Nitrate (10 patients). Another 10 patients who underwent two MSCT examinations with sublingual Nitrate administration were randomly selected from this database to serve as control group. For the resulting 40 MSCT examinations, blinded MSCT datasets were prepared, which were randomly evaluated by a reader blinded to the patient information and whether or not Nitrate had been given. The proximal coronary artery diameters were measured for the left main coronary artery (LMA), the left anterior descending coronary artery (LAD), the left circumflex coronary artery (LCX), and the right coronary artery (RCA) in all 40 datasets, resulting in altogether 160 measurements.
  
  
  RESULTS
  The proximal diameters of all four coronary arteries were significantly larger on the MSCT coronary angiograms obtained after sublingual administration of Nitrate compared with the examinations in the same 10 patients without Nitrate (p < 0.001). The average diameters without and with Nitrate for the LMA, LAD, LCX, and RCA were 4.3 +/- 1.1 vs. 4.8 +/- 0.9 mm (12 % increase, p < 0.005), 3.0 +/- 0.6 vs. 3.5 +/- 0.5 mm (17 % increase, p < 0.001), 2.7 +/- 0.6 vs. 3.2 +/- 0.7 mm (19 % increase, p < 0.005), and 2.9 +/- 0.9 vs. 3.5 +/- 0.7 mm (21 % increase, p < 0.005), respectively. In the control group of 10 patients who underwent two MSCT coronary angiographies after sublingual Nitrate, no significant difference in the proximal diameter of all four main coronary vessels was observed.
  
  
  CONCLUSIONS
  Sublingual administration of Nitrate results in significantly larger proximal coronary artery diameters on MSCT coronary angiography and might thus be recommended for routine examinations.
authors.affiliation: Institut für Radiologie, Charité, Berlin. marc.dewey@charite.de
authors.forename: M
authors.initials: M
authors.lastname: Dewey
authors.forename: H
authors.initials: H
authors.lastname: Hoffmann
authors.forename: B
authors.initials: B
authors.lastname: Hamm
mesh_terms: D000286:Administration, Sublingual; D000336:Aerosols; D000368:Aged; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis*; D023921:Coronary Stenosis / Q000175:diagnosis*; D003331:Coronary Vessels / Q000187:drug effects* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005858:Germany; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage; D011292:Premedication; D011873:Radiology Information Systems; D012016:Reference Values; D012189:Retrospective Studies; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D000336:Aerosols; D014665:Vasodilator Agents; D005996:Nitroglycerin