Arterial stiffness may vary with physiological stimulus and therefore, its quantification in dynamic conditions could enhance the characterization of vascular elastic properties. The aim of this study was to evaluate the feasibility of the assessment of carotid artery’s elasticity during exercise in terms of reproducibility.

Eighteen healthy volunteers (9 men, 34±3 years) underwent a maximal exercise testing on a graded semi-supine cycle ergometer. Ultrasound B-mode image sequences (DICOM format, high frame-rate) of right common carotid arteries were acquired at different steps (60%, 70%, 80% and 85% of maximal heart rate), and analysed by an automatic system (Carotid Studio, IFC-CNR) for the measurement of arterial diastolic diameter (D) and distension (ΔD). In addition, central pulse pressure (PPa) was estimated by tonometry (radial-aortic transfer function, Sphygmocor, AtcorMedical). Cross-sectional compliance (CC) and distensibility (DC) coefficients were then obtained for each step of the examination. Subjects were analysed in two different sessions 7 days apart, in order to evaluate intersession reproducibility of the measurements; variability was expressed as coefficient of variation (CV) for each step of the examination.

At rest CVs were 3%±3% for D, 8%±6% for ∆D, 8%±6% for PPa, 9%±8% for CC and 10%±6% for DC.

During exercise maximal variability was found at peak: 7%±5% for D, 12%±8% for ∆D, 11%±7% for PPa, 19%±6% for CC and 24%±15% DC.

The reproducibility of carotid parameters, which is excellent at rest, remains more than satisfactory during exercise. Hence, the proposed approach might be used for investigating the dynamic behaviour of arterial elasticity.