Evaluation of atrial fibrillation induced during anesthesia with fentanyl and pentobarbital in German Shepherd Dogs with inherited arrhythmias.
OBJECTIVE
To determine the type of atrial fibrillation induced by use of 2 pacing protocols during fentanyl and pentobarbital anesthesia before and after administration of atropine and to determine the organization of electrical activity in the left and right atria during atrial fibrillation in German Shepherd Dogs.


METHODS
7 German Shepherd Dogs.


METHODS
Extrastimulus and pacedown protocols were performed before and after atropine administration. Monophasic action potential spectral entropy and mean dominant frequency were calculated during atrial fibrillation.


RESULTS
Atrial fibrillation occurred spontaneously in 6 of 7 dogs. All 7 dogs had atrial fibrillation induced. Sustained atrial fibrillation occurred in 13 of 25 (52%) episodes induced by the extrastimulus protocol and in 2 of 12 episodes of atrial fibrillation induced by pacedown. After atropine administration, sustained atrial fibrillation did not occur, and the duration of the nonsustained atrial fibrillation (6 episodes in 2 dogs of 1 to 26 seconds) was significantly shorter than before atropine administration (25 episodes in 7 dogs of 1 to 474 seconds). The left atrium (3.67 +/- 0.08) had lower spectral entropy than the right atrium (3.81 +/- 0.03), indicating more electrical organization in the left atrium. The mean dominant frequency was higher in the left atrium in 3 dogs.


CONCLUSIONS
Atrial fibrillation developed spontaneously and was induced in German Shepherd Dogs under fentanyl and pentobarbital anesthesia. Electrical activity was more organized in the left atrium than in the right atrium as judged by use of spectral entropy.
Pariaut
Romain
R
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
Moïse
N Sydney
NS
Koetje
Bethany D
BD
Flanders
James A
JA
Hemsley
Shari A
SA
Farver
Thomas B
TB
Gilmour
Robert F
RF
Gelzer
Anna R M
AR
Kraus
Marc S
MS
Otani
Niels F
NF
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects*; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000235:genetics / Q000662:veterinary*; D001281:Atrial Fibrillation / Q000139:chemically induced / Q000662:veterinary*; D001285:Atropine; D004283:Dog Diseases / Q000139:chemically induced*; D004285:Dogs; D004562:Electrocardiography / Q000662:veterinary; D005283:Fentanyl / Q000008:administration & dosage / Q000009:adverse effects; D010424:Pentobarbital / Q000008:administration & dosage / Q000009:adverse effects
D018686:Anesthetics, Intravenous; D001285:Atropine; D010424:Pentobarbital; D005283:Fentanyl