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This Article Full Text Full Text (PDF) All Versions of this Article: 285/4/H1563    most recent 00384.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (27) Citing Articles via Google Scholar Google Scholar Articles by Zhou, Y.-Q. Articles by Adamson, S. L. Search for Related Content PubMed PubMed Citation Articles by Zhou, Y.-Q. Articles by Adamson, S. L.

Developmental changes in left and right ventricular diastolic filling patterns in mice

¹Samuel Lunenfeld Research Institute, Mount Sinai Hospital; ²Sunnybrook & Women's College Health Sciences Centre; Departments of ³Physiology, ⁴Obstetrics/Gynecology, and ⁵Medical Biophysics, University of Toronto; and ⁶Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X5

Submitted 29 April 2003 ; accepted in final form 30 May 2003

Developmental changes in left and right ventricular diastolic filling patterns were determined noninvasively in isoflurane-anesthetized outbred ICR mice. Blood velocities in the mitral and tricuspid orifices were recorded in 16 embryos at days 14.5 (E14.5) and 17.5 of gestation (E17.5) using an ultrasound biomicroscope and also serially in three groups of postnatal mice aged 1–7 days (n = 23), 1–4 wk (n = 18), and 4–12 wk (n = 27) using 20-MHz pulsed Doppler. Postnatal body weight increased rapidly to 8 wk. Heart rate increased rapidly from 180 beats/min at E14.5 to 380 beats/min at 1 wk after birth and then more gradually to plateau at 450 beats/min after 4 wk. Ventricular filling was quantified using the ratio of peak velocity of early ventricular filling due to active relaxation (E wave) to that of the late ventricular filling caused by atrial contraction (A wave) (peak E/A ratio) and the ratio of the peak E velocity to total time-velocity integral of E and A waves (peak E/total TVI ratio). Both ventricles had similar diastolic filling patterns in embryos (peak E/A ratio of 0.28 ± 0.02 for mitral flow and 0.27 ± 0.02 for tricuspid flow at E14.5). After birth, mitral peak E/A increased to >1 between the third and fifth day, continued to increase to 2.25 ± 0.25 at 3 wk, and then remained stable. The tricuspid peak E/A ratio increased much less but stabilized at the same age (increased to 0.79 ± 0.03 at 3 wk). The peak E/total TVI ratio showed similar left-right differences and changes with development. Age-related changes were largely due to increases in peak E velocity. The results suggest that diastolic function matures 3 wk postnatally, presumably in association with maturation of ventricular recoil and relaxation mechanisms.

mitral orifice; tricuspid orifice; pulsed Doppler; cardiac hemodynamics; ultrasound biomicroscope; isoflurane