Impact of anesthesia on cardiac function during echocardiography in mice.
Anesthetics provide sedation and immobility facilitating echocardiography in mice, but influence cardiac function. We studied the effects of intraperitoneal and inhaled anesthetic agents on echocardiographic measurements. Mice were anesthetized with intraperitoneal tribromoethanol (TBE), ketamine-midazolam (K/M), ketamine-xylazine (K/X), or inhaled isoflurane (Isf), and echocardiographic parameters were assessed at 5, 10, 15, and 20 min. In C57BL/6N mice, Isf produced high initial heart rates (HR) that decreased to levels comparable to TBE at 15-20 min (approximately 450 beats/min) and the most stable percent fractional shortening (%FS) and end-diastolic dimension (EDD). With TBE, %FS initially was low, but increased comparable to Isf (approximately 45%) at 15 min. K/M produced similar time trends but lower absolute values compared with TBE for all parameters. K/X produced cardiac depression evidenced by low HR and %FS, and increased EDD. Isf was the most reproducible in repeat studies at 12 days. In C57BL/6J compared with C57BL/6N mice, K/M produced higher HR, and %FS and TBE produced smaller EDD. In conclusion, anesthetic agent, timing of echocardiographic measurements, and genetic background are all critical variables during echocardiography in mice.
Roth
David M
DM
Veterans Affairs Medical Center of San Diego and Department of Anesthesiology, University of California, San Diego, California 92161, USA. droth@ucsd.edu
Swaney
James S
JS
Dalton
Nancy D
ND
Gilpin
Elizabeth A
EA
Ross
John
J
D000280:Administration, Inhalation; D000758:Anesthesia / Q000009:adverse effects*; D000777:Anesthetics / Q000008:administration & dosage*; D000818:Animals; D001835:Body Weight; D003971:Diastole / Q000187:drug effects; D004452:Echocardiography; D000431:Ethanol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D006321:Heart / Q000033:anatomy & histology; D006339:Heart Rate / Q000187:drug effects; D007530:Isoflurane / Q000008:administration & dosage; D007649:Ketamine / Q000008:administration & dosage; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008874:Midazolam / Q000008:administration & dosage; D009929:Organ Size; D010537:Peritoneum / Q000187:drug effects; D015203:Reproducibility of Results; D013045:Species Specificity; D013997:Time Factors; D014991:Xylazine / Q000008:administration & dosage
D000777:Anesthetics; C062527:tribromoethanol; D014991:Xylazine; D000431:Ethanol; D007649:Ketamine; D007530:Isoflurane; D008874:Midazolam