Age,Race,and Gender Influence Internal Carotid Artery Doppler Velocities in Children

Abstract

Introduction

Few data are available describing internal carotid artery pulsed-wave Doppler velocities in children. Therefore, mean values were obtained in healthy children and correlates of peak systolic (PSV) and end diastolic (EDV) velocities were determinants.

Methods

As part of an ongoing longitudinal study of cardiovascular risk factors in children, bilateral PSV and EDV were obtained in 115 subjects (age 17.0 ± 3.8 years; 37% Caucasian, 63% African American; 43% male, 57% female). Standard carotid duplex imaging was performed with a GE Vivid 7, 7–12 MHz linear array transducer. Velocities were acquired in the proximal 2 cm of each artery, placing the angle of insonation parallel to vessel wall resulting in angles of ≥50 degrees and ≤60 degrees. All velocities were measured in triplicate. Means and standard deviations of all significant variables were calculated and differences tested with t-testing. Pearson correlation coefficients between PSV, EDV, and covariates (age < or ≥ 18 years, height (HT), weight (WT), gender, systolic blood pressure) were determined. General linear models were constructed to elucidate significant determinants of velocities.

Results

Mean values for PSV and EDV differed significantly by age and race. PSV values differed by gender (all p < 0.02). Age and race correlated with PSV and EDV, whereas gender correlated only with PSV measures. In general linear models, when stratified by age groups, age and race were significant determinates of both velocities and HT only a determinate for PSV. Younger subjects had greater velocities. When stratified by race, results were similar, with Caucasians having increased velocities. When stratified by gender, no models were significant.

Conclusion

Normal PSV and EDV values are greater in children than adults and in Caucasians versus African-Americans. These may be influenced by age and race differences in HT. Proximal internal carotid pulsed Doppler velocities in children should be interpreted based by age and race.