Mouse models are increasingly employed in the comprehension of cardiovascular disease. Vascular characterization could be enriched with Wave Intensity Analysis (WIA), which provides additional information about the vascular system and its interaction with the heart. We investigated age-associated changes in vascular parameters of mice in different arterial sites and explored the role of WIA.

Five adult (5 months) and five old (16 months) wild type male mice (strain C57BL6) were examined. Instantaneous values of diameter and flow velocity were automatically achieved from carotid and abdominal aorta B-mode and PW-Doppler images and elaborated to provide the lnD-V loop; pulse wave velocity values (PWVcar and PWVabd) and relative distension measurements (relDcar and relDabd) were calculated for both carotid artery and abdominal aorta. The WIA, as introduced by Parker in 2009, was performed: the amplitudes of the first local maximum (W1_car and W1_abd) and minimum (Wb_car and Wb_abd) were calculated.

PWVcar (adult: 1.41±0.37, old: 2.19±0.49 m/s), PWVabd (1.89±0.63 vs 2.89±0.68 m/s), relDcar (27%±5.9% vs 19.7%±3.6%) and relDabd (26.2%±4.1%, vs 15.4%±3.6%) values were significantly different (p<0.05) in the two age groups. W1_abd amplitude was higher in adult than in old mice (12.9±6.7×10⁻⁷ m²/s vs 5.5±2.2×10⁻⁷ m²/s, p<0.05); the same trend was found in Wb_car amplitude (9.07±4.8×10⁻⁸ vs 4.27±1.24×10⁻⁸ m²/s), even if the difference was not significant (p=0.09).

The age-associated decrease in W1_abd may suggest a change in cardiac contractility, while that in Wb_car may be related to alterations in reflected waves from cerebral circulation. Therefore, WIA might provide additional information to standard vascular biomarkers.