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Smolich JJ, Cheung MMH, Mynard JP. Reducing lung liquid volume in fetal lambs decreases ventricular constraint. Pediatr Res. 2021;90(4):795-800doi: 10.1038/s41390-020-01352-y.
Smolich, J. J., Cheung, M. M. H., & Mynard, J. P. (2021). Reducing lung liquid volume in fetal lambs decreases ventricular constraint. Pediatric research, 90(4), 795-800. https://doi.org/10.1038/s41390-020-01352-y
Smolich, Joseph J, et al. "Reducing lung liquid volume in fetal lambs decreases ventricular constraint." Pediatric research vol. 90,4 (2021): 795-800. doi: https://doi.org/10.1038/s41390-020-01352-y
Smolich JJ, Cheung MMH, Mynard JP. Reducing lung liquid volume in fetal lambs decreases ventricular constraint. Pediatr Res. 2021 Oct;90(4):795-800. doi: 10.1038/s41390-020-01352-y. Epub 2021 Jan 27. PMID: 33504958.
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Pediatr Res. 2021 Oct;90(4):795-800. doi: 10.1038/s41390-020-01352-y. Epub 2021 Jan 27.

Reducing lung liquid volume in fetal lambs decreases ventricular constraint.

Pediatric research

Joseph J Smolich, Michael M H Cheung, Jonathan P Mynard

Affiliations

  1. Heart Research, Murdoch Children's Research Institute, Parkville, VIC, Australia. [email protected].
  2. Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia. [email protected].
  3. Heart Research, Murdoch Children's Research Institute, Parkville, VIC, Australia.
  4. Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia.
  5. Department of Cardiology, Royal Children's Hospital, Parkville, VIC, Australia.
  6. Department of Biomedical Engineering, University of Melbourne, Parkville, VIC, Australia.

PMID: 33504958 DOI: 10.1038/s41390-020-01352-y

Abstract

BACKGROUND: This study evaluated whether an increased left ventricular (LV) pump function accompanying reduction of lung liquid volume in fetal lambs was related to increased LV preload, augmented LV contractility, or both.

METHODS: Eleven anesthetized preterm fetal lambs (gestation 128 ± 2 days) were instrumented with (1) an LV micromanometer-conductance catheter to obtain LV end-diastolic volume (EDV) and end-diastolic pressure (EDP), the maximal rate of rise of LV pressure (dP/dt

RESULTS: Reducing lung liquid volume by 16 ± 4 ml kg

CONCLUSION: These findings suggest a rise in LV pump function evident after reduction of lung liquid volume in fetal lambs was related to increased LV preload secondary to lessening of external LV constraint, without any associated rise in LV contractility.

IMPACT: This study has shown that reducing the volume of liquid filling the fetal lungs lessens the degree of external constraint on the heart. This lesser constraint permits a rise in left ventricular dimensions and thus greater cardiac filling that leads to increased left ventricular pumping performance. This study has defined a mechanism whereby a reduction in lung liquid volume results in enhanced pumping performance of the fetal heart. These findings suggest that a reduction in lung liquid volume which occurs during the birth transition contributes to increases in left ventricular dimensions and pumping performance known to occur with birth.

© 2021. The Author(s), under exclusive licence to the International Pediatric Research Foundation, Inc.

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