Related Experiment Videos
Age-related variation in contractility estimate in patients less than or equal to 20 years of age
T R Kimball1, S R Daniels, P Khoury
1Division of Cardiology, Children's Hospital Medical Center, University of Cincinnati College of Medicine, Ohio 45229.
Insights
The relationship between velocity of circumferential fiber shortening (VCF) and wall stress (WS) is reproducible and age-dependent in children. This VCF-WS relation, crucial for assessing cardiac function, varies significantly with age but not sex.
Area of Science:
- Pediatric Cardiology
- Cardiac Physiology
- Echocardiography
Background:
- The velocity of circumferential fiber shortening (VCF) and wall stress (WS) relationship is vital for estimating cardiac contractile state.
- Its dependence on age in pediatric populations has not been previously established.
Purpose of the Study:
- To determine the reproducibility of the VCF-WS relation.
- To investigate the dependence of the VCF-WS relation on age and sex in normal children.
Main Methods:
- Echocardiography was used to measure VCF and WS in 204 normal children across three age groups.
- Serial echocardiography was performed on a subset of children to assess reproducibility.
- Statistical analysis examined the relationship between VCF and WS, considering age and sex.
Main Results:
- The VCF-WS relation demonstrated high reproducibility over time.
- A significant inverse linear relationship between VCF and WS was observed in all age groups (p < 0.001).
- The VCF-WS relation was age-dependent, with younger children (especially < 6 months) exhibiting steeper regression lines and higher y-intercepts, indicating greater VCF dependence on WS. No sex-based differences were found.
Conclusions:
- The VCF-WS relation is a reproducible measure of cardiac contractility in children.
- This relationship is significantly influenced by age, particularly in infants under six months.
- Gender does not affect the VCF-WS relationship in pediatric populations.
Abstract:
The relation between velocity of circumferential fiber shortening (VCF) and wall stress (WS) is being used to estimate contractile state in a variety of disease states and patient ages more frequently. However, its relation to age has not been established. To determine reproducibility and age and sex dependence of this relation, 204 normal children (113 boys, 91 girls) underwent echographic determination of VCF and WS. The children were enrolled in 3 groups: group 1 less than 6 months old (n = 27); group 2 greater than 6 months and less than 3 years old (n = 38); and group 3 greater than 3 and less than 20 years old (n = 139). Twenty-five children also underwent serial echocardiography (n = 44) to determine reproducibility of the relation. Only 1 of the 44 repeat data pairs of VCF and WS was outside the 95% confidence limits of that relation. In all 3 groups, VCF was significantly inversely and linearly related to WS (p less than 0.001). The regression equation in the oldest group was very similar to previous reports (VCF = -0.0031 [WS] + 1.21). The regression lines in the 2 younger groups were significantly steeper and had a significantly higher y-intercept (p less than 0.01). Group 1 had the steepest slope and highest y-intercept. There was no difference in the regression lines of different sexes in any of the patient groups. It is concluded that the relation of VCF to WS is reproducible over time. It is age-dependent but has no relation to gender. VCF in patients less than 6 months old is more highly dependent on WS.(ABSTRACT TRUNCATED AT 250 WORDS)