Therapy
Preoperative β-blocker
Dosage*:Any in usual therapeutic dose (ie, metoprolol 50 mg PO q12h or q8h for at least 2 preoperative days, day of surgery, and at least 6 postoperative days)
Odds ratio†:0.39 (0.28-0.52)
Cautions:Reactive airways disease, decompensated CHF
Adverse effects:
  • Sinus bradycardia
  • AV block
  • Hypotension
  • Bronchospasm
Preoperative amiodarone
Dosage*:10 mg/kg/d (rounded to nearest 100 mg) divided into 2 daily PO dosages for 6 preoperative days, day of surgery, and 6 postoperative days
Odds ratio†:0.61 (0.50-0.74)
Cautions:30%-50% reduction in the dosages of other drugs with antiarrhythmic or sinus/AV nodal effects and warfarin will be required
Adverse effects:
  • Sinus bradycardia
  • AV block
  • Hypotension
  • Torsade de pointes VT (rare)
  • Pulmonary toxicity (rare)
Postoperative amiodarone
Dosage*:900-1200 mg IV over 24 hrs beginning within 6 hrs of surgery, then 400 mg PO TID each of the next 4 days
Odds ratio†:0.53 (0.39-0.71)
Cautions:30%-50% reduction in the dosages of other drugs with antiarrhythmic or sinus/AV nodal effects and warfarin will be required
Adverse effects:
  • Sinus bradycardia
  • AV block
  • Hypotension
  • Torsade de pointes VT (rare)
  • Pulmonary toxicity (rare)
Magnesium sulfate
Dosage*:1.5 g IV over 4 hrs first preoperative days, immediately postoperatively, and next 4 postoperative days. Other trials have omitted the preoperative dosage
Odds ratio†:0.83 (0.65-1.06)
Cautions:Renal failure
Adverse effects:
  • Hypotension (rare)
  • Sedation (very rare)
  • Respiratory depression (very rare)
Atrial pacing
Dosage*:Right, left, or biatrial pacing for 3-4 days postoperatively. Rate set to overdrive sinus rate either manually or using sensing algorithms
Odds ratio†:0.67 (0.54-0.84)
Cautions:May increase atrial tachyarrhythmias if pacing continues in setting of sensing malfunction
Adverse effects:
  • Diaphragmatic stimulation, Increased myocardial oxygen requirements, ? Increased infection rate

AV, atrioventricular; CHF, congestive heart failure; VT, ventricular tachycardia.
*Dosages used in the randomized studies vary widely and the optimal dosages for this indication have not been established. The dosages provided are those used in the largest positive trial of that therapy and are referenced to that study.
† The odds ratios provided are from meta-analyses of the studies of each prophylactic approach (not for the single study referenced for dosage). Comparisons of the efficacies of various prophylactic approaches require randomized trials, which, for the most part, have not been performed. Accordingly, comparisons of the odds ratios provided in the table should be avoided.