Affiliation: Department of Anaesthesiology, Hospital Clínico Universitario San Carlos, C/ Porfesor Martin Lagos s/n. C.P: 28040. Madrid. Spain.
Remifentanil is a selective mu-opioid receptor agonist characterized by a rapid onset and ultrashort predictable duration of action providing intense analgesia without prolonged respiratory depression. Remifentanil has been implicated in the causation of intraoperative bradyarrhythmias and asystole both in adults and in pediatric patients. Electrophysiological studies in humans and animals show that remifentanil provokes a dose-dependent depressor effect on sinus and AV node function, manifested by a significant prolongation of sinus node recovery time, sino-atrial conduction time and Wenckebach cycle length. These electrophysiologic effects of remifentanil suggest that it should be used with attention in vulnerable patients with predisposition to bradiarritmias during anesthesia.