title: Best anesthetics for assessing left ventricular systolic function by echocardiography in mice.
abstract: Our review of the literature of the major cardiovascular journals for the past three years showed that for all studies using anesthesia for mouse echocardiography, the predominant anesthetic was isoflurane, which was used in 76% of the studies. The goal of this investigation was to determine if isoflurane is indeed the best anesthetic. Accordingly, we compared isoflurane with 2,2,2-tribromoethanol (Avertin), ketamine-xylazine, and ketamine on different days in the same 14 mice, also studied in the conscious state without anesthesia. A randomized crossover study design was employed to compare the effects on left ventricular (LV) systolic function and heart rate of the four different anesthetic agents assessed by transthoracic echocardiography. As expected, each anesthetic depressed LV ejection fraction and heart rate when compared with values in conscious mice. Surprisingly, isoflurane was not the best, but actually second to last in maintaining normal LV function and heart rate. The anesthetic with the least effect on LV function and heart rate was ketamine alone at a dose of 150 mg/kg, followed by Avertin at 290 mg/kg, isoflurane at 3% induction and 1 to 2% maintenance, and lastly ketamine-xylazine at 100 and 10 mg/kg, respectively. In summary, these results indicate that ketamine alone exerts the least depressant effects on LV function and heart rate, with Avertin second, suggesting that these anesthetics should be used when it is not feasible to study the animals in the conscious state as opposed to the most commonly used anesthetic, isoflurane.
authors: Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark, New Jersey; and.
authors: Ronald E
authors: RE
authors: Pachon
authors: Comparative Medicine Resources, Rutgers-New Jersey Medical School, Newark, New Jersey.
authors: Bruce A
authors: BA
authors: Scharf
authors: Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark, New Jersey; and.
authors: Dorothy E
authors: DE
authors: Vatner
authors: Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark, New Jersey; and vatnersf@njms.rutgers.edu.
authors: Stephen F
authors: SF
authors: Vatner
mesh_terms: D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D000431:Ethanol / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000187:drug effects*; D007530:Isoflurane / Q000494:pharmacology; D007649:Ketamine / Q000494:pharmacology*; D008297:Male; D051379:Mice; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D011237:Predictive Value of Tests; D013318:Stroke Volume / Q000187:drug effects; D013599:Systole; D014463:Ultrasonography; D016277:Ventricular Function, Left / Q000187:drug effects*; D014991:Xylazine / Q000494:pharmacology
chemical_list: D000777:Anesthetics; C062527:tribromoethanol; D014991:Xylazine; D000431:Ethanol; D007649:Ketamine; D007530:Isoflurane
keywords: anesthetics; conscious state; echocardiography; mice