These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Noninvasive assessment of myocardial contractility, preload, and afterload in healthy newborn infants.
    Author: Rowland DG, Gutgesell HP.
    Journal: Am J Cardiol; 1995 Apr 15; 75(12):818-21. PubMed ID: 7717287.
    Abstract:
    Assessment of ventricular contractility in the newborn infant using standard echocardiographic indexes can result in error due to the unique physiologic state that exists in the neonatal period. It has been suggested from animal and human studies that maturational alterations in contractility occur with birth and continue throughout infancy. To further investigate these developmental changes, 41 newborn infants aged 3 to 10 days and 37 children aged 3 to 18 years were evaluated with 2-dimensional and M-mode echocardiography. The rate-corrected velocity of circumferential fiber shortening (VCFc)-end-systolic wall stress (ESWS) relation was used as a load-independent estimate of contractility. Preload, afterload, and ventricular mass were also measured. Despite similar shortening fractions, the infant group had significantly higher mean VCFc and lower ESWS than the older age group (1.28 vs 1.08 circ/s and 30.2 vs 37.3 gm/m2, respectively). An inverse linear relation between VCFc and ESWS was found in both age groups. The y-intercept was higher in the infant group (p < 0.01), and the slope of the mean regression line was steeper than in the older children (p < 0.01). Ventricular mass in relation to body surface area increased with age. We conclude that (1) newborn infants have a higher basal contractile state that cannot be accounted for by lower afterload, (2) myocardial performance is more sensitive to afterload in the immature heart, and (3) shortening fraction may underestimate ventricular function in the newborn.
    [Abstract] [Full Text] [Related] [New Search]