Quantitative evaluation of carotid elasticity in normal adults by echo tracking technique

Objective With echo tracking technique, the normal values of carotid stiffness and compliance and the related influencing facts were determined in normal adults for their potential clinical applications. Methods The study population included 143 normal adults with 72 males and 71 females at a mean age of ( 47.2 ± 14.9 )years. The changes of the carotid diameter during cardiac cycles were obtained and the quantitative parameters of pressure strain elastic modulus(Ep), stiffness(β) and the arterial compliance(AC) were calculated automatically. Their possible influencing clinical variables such as age, gender, heart rate and blood pressure were analyzed. Results ① Age showed the strongest correlation with all the parameters while systolic blood pressure showed a significant correlation with Ep. Gender, heart rate and diastolic blood pressure showed no correlation with these parameters. ② The subjects were divided into 5 age groups and the parameters among the age groups were compared. In subjects 40 years old, Ep and β increased while AC decreased with the increase of age. In subjects ≥40 years old, Ep, β and AC showed no significant change with age. ③ The normal values of Ep, β and AC in subjects ≥40 years old were 117.97 ± 31.04 , 8.67 ± 2.23 and 0.74 ± 0.21 respectively, while these parameters changed with age in subjects 40 years old. Conclusions The stiffness and compliance of carotid were correlated significantly with age, and the echo tracking technique may be a promising modality for noninvasive estimation of arterial elastic function.