Objective—To determine the effect of sevoflurane
on cardiac energetic and hemodynamic parameters in
Animals—7 healthy domesticated ferrets.
Procedure—Sevoflurane was used as the sole anesthetic
agent for general anesthesia in ferrets.
Standard midline laparotomy and median sternotomy
were performed to permit instrumentation.
Myocardial blood flow was determined by use of colored
microsphere technology. Measurements and
blood samples were obtained at 1.25%, 2.5%, and
3.75% expired concentration of sevoflurane.
Results—A dose-dependent decrease in arterial
blood pressure, left ventricular pressure, systemic
vascular resistance, aortic flow, and dp/dt (an index of
contractility) was detected as expired concentration
of sevoflurane increased. Heart rate, central venous
pressure, coronary vascular resistance, myocardial
oxygen extraction ratio, and (the time constant of
relaxation) were unchanged. Cardiac external work
decreased, as did myocardial oxygen consumption,
causing increased cardiac efficiency at higher concentrations
Conclusions and Clinical Relevance—Sevoflurane
caused minimal and predictable cardiovascular effects
in ferrets without increasing myocardial metabolic
demands. Data obtained from this study have not
been previously reported for a species that is being
commonly used in cardiovascular research. These
findings also support use of sevoflurane as a safe
inhalant anesthetic in ferrets for clinical and research
settings. ( Am J Vet Res 2004:65:653–658)
Objective—To evaluate the anatomic distribution and electrophysiologic properties of accessory pathways (APs) in dogs.
Animals—10 dogs with tachyarrhythmias associated with an AP.
Procedures—Each dog underwent electrophysiologic testing to determine the inducibility of documented and undocumented arrhythmias and to identify location, conduction properties, and antegrade and retrograde effective refractory periods of the APs. Radiofrequency catheter ablation was then performed.
Results—15 APs were identified; 7 dogs each had a single AP, and 3 had multiple APs. Fourteen of the 15 APs were right-sided (6 right free wall, 4 posteroseptal, 3 midseptal, and 1 anteroseptal), and 1 was left-sided (left free wall). All APs conducted in an all-or-none fashion. Unidirectional retrograde conduction was observed in 11 APs, and bidirectional conduction was observed in 4. All documented tachyarrhythmias could be induced during electrophysiologic testing; atrial fibrillation was also inducible in 2 dogs. Mean ± SD cycle duration of orthodromic atrioventricular reciprocating tachycardia was 215.80 ± 44.87 milliseconds. Mean shortest R-R interval during atrial fibrillation was 247.33 ± 83.17 milliseconds.
Conclusions and Clinical Relevance—Results suggested that in dogs, most APs are right-sided, had unidirectional retrograde conduction, and are associated with various arrhythmias, including orthodromic atrioventricular reciprocating tachycardia and atrial fibrillation without evidence of pre-excitation.