Systemic Arterial Pressure-Volume Relationship and Vasomotor Tone: A One-Dimensional Viscoelastic Approach

Pressure-Volume (PV) loops are commonly utilized for left ventricular cardiac assessment, and have been extensively studied. However, the PV relationship in the systemic arterial system (SAS) domain remains poorly understood. The main objective of this work was to evaluate the SAS PV-loops dynamic behavior, in terms of the distributed nature of SAS and the impact of vascular smooth muscle tone (VSMT). A One-dimensional (1D) model of arterial vasculature was used to SAS PV-loop assessment. The results were analyzed in terms of those obtained from the generalization of the Windkessel model, together with an increase of arterial wall viscosity (VSMT augmentation). A similar behavior was observed between the two approaches, indicating the consistency of the 1D model in revealing the morphology of SAS PV-loop. Additionally, the enclosed area of the SAS PV-loop was influenced by increased VSMT, with an elevation of aortic pulse wave velocity. The use of a complete human vascular 1D model allowed the assessment of the SAS PV-loop, enabling the study of its dynamic nature as well as its relationship with SAS energy dissipation.