Antiarrhythmic and cardioprotective effects of remifentanil in anesthetized dogs.
OBJECTIVE
To study the antiarrhythmic effect of remifentanil in experimental arrhythmias in dogs.


METHODS
We used dogs weighing 12 kg-18 kg anesthetized with 30 mg/kg sodium pentobarbital given intravenously. Ventricular arrhythmia, ventricular fibrillation and death were induced with digoxin (9 microg/kg/min). In another model, two types of arrhythmia were induced in the right atrium, one of them with aconitine crystals placed on the right atrium and the other was induced in the basement of the right atrium by electrical stimulation. The potential antiarrhythmic action of remifentaniL was investigated in ventricular and atrial arrhythmias by the administration of an intravenous bolus after toxic signs were evident. Thus, two arrhythmias with different mechanisms were generated. Leads DII, unipolar left intraventricular and right atrial leads, and left ventricular pressure were used to record control tracings and tracings in presence of remifentanil, during ventricular arrhythmia.


RESULTS
Remifentanil abolished toxic effects of digoxin, it eliminated the A-V dissociation and ventricular extrasystoles, reverting to sinus rhythm in each case. Remifentanil extended the time to reach lethal doses from 63.25 +/- 11.3 to 100 +/- 11.8 min. These effects were blocked by naloxone (0.01 microg/kg) applied before remifentanil. In the two arrhythmias model, remifentanil suppressed both, ectopic focus and atrial flutter.


CONCLUSIONS
Remifentanil elicits antiarrhythmic and cardioprotective effects in experimental ventricular arrhythmias induced by digoxin and in a model of two atrial arrhythmias induced by aconitine and by electrical stimulation.
Luna-Ortiz
Pastor
P
Departamento de Farmacología, Instituto Nacional de Cardiología Ignacio Chávez, México.
Zarco-Olvera
Gabriela
G
Ramírez-Ortega
Margarita
M
Tenorio-López
Fermin A
FA
Gutiérrez
Alfonso
A
Martínez-Rosas
Martín
M
Del-Valle Mondragón
Leonardo
L
Pastelín
Gustavo
G
D000701:Analgesics, Opioid / Q000627:therapeutic use*; D000758:Anesthesia; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000517:prevention & control*; D004285:Dogs; D005260:Female; D006331:Heart Diseases / Q000517:prevention & control*; D008297:Male; D010880:Piperidines / Q000627:therapeutic use*; D000077208:Remifentanil
D000701:Analgesics, Opioid; D010880:Piperidines; D000077208:Remifentanil