Abstract 6281: Variations in Carotid Artery Intima-Media Thickness during the Cardiac Cycle in Children
There is paucity of research looking at physiologic factors that can influence carotid artery intima-media thickness (CIMT) measurement in children. To ascertain if CIMT measurements in children need to be performed at a specific point in the cardiac cycle. We determined CIMT in children with obesity, hypertension, dyslipidemia, and/or familial hypercholesterolemia. CIMT was measured at various points during the cardiac cycle using an EKG as a guide in order to note the relation between the phase of the cardiac cycle and CIMT. 49 children, 6–19 yrs of age, underwent a carotid ultrasound using a high resolution probe. CIMT was measured as an average of at least 100 frames for each study using a semi-automated edge detection software. The region of interest was the far wall of the common carotid artery, 2 cm proximal to the bifurcation. CIMT immediately before, during, and immediately after the QRS complex (end diastole) were analyzed separately from the other CIMT. Chronological age was 13.2 ± 3.4 yrs. 37 (75.5%) were white. 27 (55.1%) were male. Weight was 65.0 ± 24.4 kg with 28 (57.1%) > 95th %ile for age. Body mass index was 26.1 ± 6 kg/m2 with 30 (61.2%) > 95th %ile for age. Systolic blood pressure was 119.0 ± 12.8 mm Hg with 13 (26.5%) > 95th %ile for sex, age and height. Fasting lipid profile: total cholesterol was 220.0 ± 52.7 mg/dL, triglyceride 149.2 ± 80.0 mg/dL, LDL cholesterol 147.5 ± 49.1 mg/dL, HDL cholesterol 45.0 ± 13.7 mg/dL, non-HDL cholesterol 175.1 ± 47.8 mg/dL. There was a significant difference between CIMT during end-diastole compared to the rest of the cardiac cycle (table⇓) and CIMT was thicker during end-diastole. In addition CIMT had a positive linear correlation with weight and body mass index and a negative linear correlation with HDL cholesterol. CIMT should be measured during end-diastole (QRS on EKG) in children. Increased body weight and low HDL cholesterol are associated with increased CIMT in children.