title: Safety of an i.v. β-adrenergic blockade protocol for heart rate optimization before coronary CT angiography.
abstract: OBJECTIVE
  The purpose of this study was to assess the safety of heart rate optimization by use of β-adrenergic blockade solely by the i.v. route before coronary CT angiography.
  
  
  METHODS
  The records of 679 patients undergoing CT coronary angiography after receiving i.v. β-adrenergic blockade were retrospectively analyzed. Health screening was completed before scanning, and heart rate was optimized by administration of i.v. metoprolol titrated to a maximum of 70 mg to achieve a heart rate less than 65 beats/min.
  
  
  RESULTS
  The median i.v. dose was 20 mg (range, 5-70 mg). The 679 patients analyzed had a total of 10 complications (1.47%). Major complications, defined as not resolving with observation and analgesia alone, occurred in only three patients (0.44%). These complications included a second-degree atrioventricular block. A total of 299 patients (44.0%) needed more than 20 mg of i.v. metoprolol to achieve target heart rate. Only three patients needed the maximum i.v. dose of 70 mg metoprolol. Target heart rate was reached successfully in 666 patients (98.1%) with doses of less than 70 mg. This study did not show a statistically significant association between increasing complication frequency and increasing dose.
  
  
  CONCLUSIONS
  This study showed that high doses of i.v. metoprolol can be used effectively and with a low rate of major complications to control heart rate before coronary CT angiography in correctly screened patients.
authors.affiliation: 1 Department of Clinical Radiology, Heart of England NHS Foundation Trust, Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS, UK.
authors.forename: Rahil H
authors.initials: RH
authors.lastname: Kassamali
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Kim
authors.forename: Hiten
authors.initials: H
authors.lastname: Patel
authors.forename: Nitin
authors.initials: N
authors.lastname: Raichura
authors.forename: Edward T D
authors.initials: ET
authors.lastname: Hoey
authors.forename: James
authors.initials: J
authors.lastname: Hodson
authors.forename: Shahid
authors.initials: S
authors.lastname: Hussain
mesh_terms: D000293:Adolescent; D058671:Adrenergic beta-1 Receptor Antagonists / Q000008:administration & dosage / Q000009:adverse effects; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000139:chemically induced* / Q000517:prevention & control*; D017023:Coronary Angiography / Q000009:adverse effects / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage / Q000009:adverse effects*; D008875:Middle Aged; D061214:Patient Safety; D011292:Premedication / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D018570:Risk Assessment; D014057:Tomography, X-Ray Computed / Q000009:adverse effects / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D058671:Adrenergic beta-1 Receptor Antagonists; D008790:Metoprolol
keywords: complications; coronary CT angiography; ischemic heart disease; metoprolol; safety; side effects; β-blockers