A comment on the physiological basis for longitudinal motion of the arterial wall

The longitudinal motion and the intramural shear strain of the arterial wall increase dramatically in response to blood pressure, thereby impacting the vascular wall microenvironment. Exposure to a sedentary lifestyle has been identified as an independent risk factor for cardiovascular disease, but it has been shown that intermittent physical activity embedded into everyday life is enough to improve cardiovascular health. Marked changes in longitudinal motion already at low workload may explain this finding. However, to understand the mechanism linking longitudinal motion and cardiovascular health, an understanding of the physiological basis for the longitudinal motion of the arterial wall is needed. The factors underlying the longitudinal motion of the arterial wall in vivo are numerous and intertwined. As a comment and complement to the recent review by Athaide et al., we propose and discuss a comprehensive cardiovascular mechanical scenario based on current literature. In this scenario, blood pressure, typically acting in the radial direction, also acts directly in the longitudinal direction through a tapered geometry. This complements ventricular contraction, ventricular-vascular coupling, arterial diameter change, arterial stiffness in both the radial and longitudinal directions, and pre-stretch of the arterial wall. Additionally, we consider the geometry of the arterial tree and intramural friction of the arterial wall. Together, these important cardiovascular mechanical -factors form the pattern of longitudinal motion of the arterial wall, indicating that the longitudinal motion of the arterial wall is important for cardiovascular health.