title: Reference values from M-mode and Doppler echocardiography for normal Syrian hamsters.
abstract: OBJECTIVE
  Echocardiography has recently been introduced to small animal research, allowing serial measurements of cardiac diseases. In addition, the hamster model has been increasingly used, as it mimics many human heart conditions. However, no reference range of echocardiographic values reflecting normal left ventricular (LV) function exists for hamsters. The purpose of this study was to provide one.
  
  
  RESULTS
  The study group consisted of 118 10-week-old, female, Syrian golden hamsters, which underwent high-resolution echocardiography. LV mass was calculated using the corrected cube formula, and LV systolic and diastolic function were assessed by fractional shortening and mitral inflow pulsed-wave Doppler, respectively. The myocardial performance index (MPI) measured the time spent in isovolumic activity and reflected both systolic and diastolic function. The mean+/-SD LV mass, fractional shortening, and MPI were 0.19+/-0.04 g, 44.7+/-6.6%, and 0.39+/-0.1, respectively. E and A waves were differentiated in 52% of all animals. Logistic regression adjusted with a cutoff of 378 bpm revealed that the risk of E/A wave fusion was 35 times greater (95% CI: 12.6; 98.4) in animals with a heart rate >378 bpm.
  
  
  CONCLUSIONS
  This study documents echocardiographic characteristics in normal Syrian hamsters, which can be used as control values for future studies.
authors.affiliation: Cardiomyopathies Unit, Heart Institute (InCor), University of São Paulo Medical School, Av Jandira 185 ap41B Moema, São Paulo 04080-000, Brazil. verasalemi@uol.com.br
authors.forename: Vera M C
authors.initials: VM
authors.lastname: Salemi
authors.forename: Angelina M B
authors.initials: AM
authors.lastname: Bilate
authors.forename: Félix J A
authors.initials: FJ
authors.lastname: Ramires
authors.forename: Michael H
authors.initials: MH
authors.lastname: Picard
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Gregio
authors.forename: Jorge
authors.initials: J
authors.lastname: Kalil
authors.forename: Edécio Cunha
authors.initials: EC
authors.lastname: Neto
authors.forename: Charles
authors.initials: C
authors.lastname: Mady
mesh_terms: D000818:Animals; D006224:Cricetinae; D003971:Diastole / Q000502:physiology; D004452:Echocardiography / Q000592:standards*; D015150:Echocardiography, Doppler / Q000592:standards; D005260:Female; D006339:Heart Rate; D006352:Heart Ventricles / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008647:Mesocricetus; D023421:Models, Animal; D012016:Reference Values; D013599:Systole / Q000502:physiology; D016277:Ventricular Function, Left