Intraoperative loading dose of amiodarone for prophylaxis against atrial fibrillation after valvular heart surgery

Benefit of amiodarone in restoring sinus rhythm (SR) after cardiac surgery was concluded in previous studies that used different protocols for giving amiodarone. The purpose of this study was to assess the use of single parenteral intraoperative loading dose of amiodarone without maintenance as prophylaxis against atrial fibrillation (AF) after valvular heart surgery.

This was a prospective, randomized, double-blind controlled study on 94 patients listed for valvular heart surgery. The patients received either amiodarone, 3 mg/kg diluted in 100 ml of normal saline and started prior to making skin incision and administrated through venous line over a period of 30 minutes, or the same volume of normal saline infused in a similar fashion. The incidence of AF during the first 5 days after surgery was the main outcome measured.

There was significant difference in favor of the amiodarone group regarding restoration of sinus rhythm after aortic cross-clamp removal, number of patients requiring cardioversion, incidence of AF and the time elapsed before incidence of it postoperatively (P values=0.02, 0.04, 0.02, 0.02, respectively). There was no difference in hospital mortality, major postoperative morbidity, intensive care unit (ICU) stay or hospital stay.

Amiodarone prophylaxis in a single intraoperative dose was significantly effective in prevention of new-onset postoperative AF after valvular heart surgery. This amiodarone dose is well tolerated and not associated with postoperative complications.