High-frequency ultrasound assessment of the murine heart from embryo through to juvenile.
OBJECTIVE
The aim of this study is to assess the murine heart of normal embryos, neonates, and juveniles using high-frequency ultrasound.


METHODS
Diastolic function was measured with E/A ratio (E wave velocity/A wave velocity) and isovolumetric relaxation time (IRT), systolic function with isovolumetric contraction time (ICT), percentage fractional shortening (FS %), percentage ejection fraction (EF %). Global cardiac performance was quantified using myocardial performance index (MPI).


RESULTS
Isovolumetric relaxation time remained stable from E10.5 to 3 weeks. Systolic function (ICT) improved with gestation and remained stable from E18.5 onward. Myocardial performance index showed improvement in embryonic life (0.82- 0.63) and then stabilized from 1 to 3 week (0.60-0.58). Percentage ejection fraction remained high during gestation (77%-69%) and then decreased from the neonate to juvenile (68%-51%).


CONCLUSIONS
The ultrasound biomicroscope allows for noninvasive in-depth assessment of cardiac function of embryos and pups. Detailed physiological and functional cardiac function readouts can be obtained, which is invaluable for comparison to mouse models of disease.
UCD School of Medicine and Medical Science, University College Dublin, Belfield, Dublin, Ireland.
Niamh
N
Corrigan
Derek P
DP
Brazil
Fionnuala M
FM
Auliffe
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D003971:Diastole / Q000502:physiology; D015150:Echocardiography, Doppler / Q000295:instrumentation* / Q000379:methods*; D005260:Female; D006321:Heart / Q000196:embryology / Q000254:growth & development / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D033401:Microscopy, Acoustic / Q000295:instrumentation* / Q000379:methods*; D009200:Myocardial Contraction / Q000502:physiology; D011247:Pregnancy; D013318:Stroke Volume / Q000502:physiology; D013599:Systole / Q000502:physiology