title: [Usefulness and safety of propranolol injection into vein for acquisition of coronary multidetector-row computed tomography].
abstract: BACKGROUND
  A low heart rate (HR), associated with a prolonged slow filling phase (SF), is necessary to obtain a high quality coronary CT at a low radiation dose with conventional 64 multidetector-row computed tomography (MDCT). The purpose of our study was to confirm the safety of injecting propranolol (2-10 mg) into the vein for lowering heart rate in patients requiring MDCT and to document the effect of the drug on HR, PQ and SF.
  
  
  METHODS
  Of 1290 consecutive patients who were initially considered for enrollment in the coronary MDCT study, 40 patients with atrial fibrillations, 3 with atrial flutters, and 13 with artificial pacemakers were excluded. Of the remaining 1234 patients (M/F=714/520), 331 had already taken an oral beta-blocker before the CT examination, and were included in the study. In patients with no contraindications, propranolol was aggressively injected (2-10 mg) into the vein to reduce the HR.
  
  
  RESULTS
  In patients not taking an oral beta blocker, 2 mg propranolol reduced the HR by -10±5 bpm and 10 mg, by -20±7 bpm. However, in patients taking an oral beta-blocker, the decrease in HR by propranolol was minimal (2 mg, -6±4 bpm; 10 mg, -10±6 bpm). Propranolol significantly prolonged the PQ interval (from 169±27 to 179±29 ms, P<0.0001), and SF (from 125±69 to 264±79 ms, P<0.0001). Adverse effects of propranolol injection were observed in only 3 [2 mild hypotension and 1 paroxysmal atrial fibrillation (recovered to sinus rhythm by DC counter shock)] of 3212 patients. All 3 patients became stable after 1 or 2 hours of rest and could return home.
  
  
  CONCLUSIONS
  Propranolol injection was a relatively safe and useful method to reduce HR and prolong SF, necessary for obtaining high quality coronary MDCT with a low radiation dose.
authors.affiliation: Department of Radiological Technology, Takase Clinic, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Sekine
authors.forename: Takahide
authors.initials: T
authors.lastname: Kodama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kondo
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Fujimoto
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Matsutani
authors.forename: Takehiro
authors.initials: T
authors.lastname: Arai
authors.forename: Hitomi
authors.initials: H
authors.lastname: Morita
authors.forename: Tomonari
authors.initials: T
authors.lastname: Sano
authors.forename: Yuji
authors.initials: Y
authors.lastname: Saito
authors.forename: Shinichi
authors.initials: S
authors.lastname: Takase
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D000368:Aged; D017023:Coronary Angiography / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D011433:Propranolol / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D036542:Tomography, Spiral Computed / Q000379:methods*
chemical_list: D000319:Adrenergic beta-Antagonists; D011433:Propranolol