title: Standardized echocardiographic assessment of cardiac function in normal adult zebrafish and heart disease models.
abstract: The zebrafish (Danio rerio) is an increasingly popular model organism in cardiovascular research. Major insights into cardiac developmental processes have been gained by studies of embryonic zebrafish. However, the utility of zebrafish for modeling adult-onset heart disease has been limited by a lack of robust methods for in vivo evaluation of cardiac function. We established a physiological protocol for underwater zebrafish echocardiography using high frequency ultrasound, and evaluated its reliability in detecting altered cardiac function in two disease models. Serial assessment of cardiac function was performed in wild-type zebrafish aged 3 to 12 months and the effects of anesthetic agents, age, sex and background strain were evaluated. There was a varying extent of bradycardia and ventricular contractile impairment with different anesthetic drugs and doses, with tricaine 0.75 mmol l-1having a relatively more favorable profile. When compared with males, female fish were larger and had more measurement variability. Although age-related increments in ventricular chamber size were greater in females than males, there were no sex differences when data were normalized to body size. Systolic ventricular function was similar in both sexes at all time points, but differences in diastolic function were evident from 6 months onwards. Wild-type fish of both sexes showed a reliance on atrial contraction for ventricular diastolic filling. Echocardiographic evaluation of adult zebrafish with diphtheria toxin-induced myocarditis or anemia-induced volume overload accurately identified ventricular dilation and altered contraction, with suites of B-mode, ventricular strain, pulsed-wave Doppler and tissue Doppler indices showing concordant changes indicative of myocardial hypocontractility or hypercontractility, respectively. Repeatability, intra-observer and inter-observer correlations for echocardiographic measurements were high. We demonstrate that high frequency echocardiography allows reliable in vivo cardiac assessment in adult zebrafish and make recommendations for optimizing data acquisition and analysis. This enabling technology reveals new insights into zebrafish cardiac physiology and provides an imaging platform for zebrafish-based translational research.
authors.affiliation: Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia.|Faculty of Medicine, University of New South Wales, Kensington, New South Wales 2052, Australia.|Department of Cardiology, St Vincent's Hospital, Darlinghurst, New South Wales 2010, Australia.
authors.forename: Louis W
authors.initials: LW
authors.lastname: Wang
authors.affiliation: Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia.|Faculty of Medicine, University of New South Wales, Kensington, New South Wales 2052, Australia.
authors.forename: Inken G
authors.initials: IG
authors.lastname: Huttner
authors.affiliation: Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia.|Faculty of Medicine, University of New South Wales, Kensington, New South Wales 2052, Australia.
authors.forename: Celine F
authors.initials: CF
authors.lastname: Santiago
authors.affiliation: Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia.|Faculty of Medicine, University of New South Wales, Kensington, New South Wales 2052, Australia.
authors.forename: Scott H
authors.initials: SH
authors.lastname: Kesteven
authors.affiliation: Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia.|Faculty of Medicine, University of New South Wales, Kensington, New South Wales 2052, Australia.
authors.forename: Ze-Yan
authors.initials: ZY
authors.lastname: Yu
authors.affiliation: Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia.|Faculty of Medicine, University of New South Wales, Kensington, New South Wales 2052, Australia.|Department of Cardiology, St Vincent's Hospital, Darlinghurst, New South Wales 2010, Australia.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Feneley
authors.affiliation: Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia d.fatkin@victorchang.edu.au.|Faculty of Medicine, University of New South Wales, Kensington, New South Wales 2052, Australia.|Department of Cardiology, St Vincent's Hospital, Darlinghurst, New South Wales 2010, Australia.
authors.forename: Diane
authors.identifier: 0000-0002-9010-9856
authors.initials: D
authors.lastname: Fatkin
mesh_terms: D000375:Aging / Q000502:physiology*; D059925:Anatomic Landmarks; D000740:Anemia / Q000473:pathology; D000758:Anesthesia; D000818:Animals; D049628:Body Size; D004167:Diphtheria Toxin; D004195:Disease Models, Animal; D004452:Echocardiography / Q000592:standards*; D005240:Feasibility Studies; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006334:Heart Function Tests / Q000592:standards*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D008297:Male; D009200:Myocardial Contraction; D009205:Myocarditis / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology; D009929:Organ Size; D012015:Reference Standards; D015203:Reproducibility of Results; D016277:Ventricular Function, Left; D015027:Zebrafish / Q000502:physiology*
chemical_list: D004167:Diphtheria Toxin
keywords: Cardiac physiology; Echocardiography; Heart failure; Regeneration; Sex differences; Zebrafish