Assessment of a Global Arterial Viscosity Modulus Using the Pressure-Volume Relationship of the Systemic Arterial...

The analysis of the left ventricular (LV) Pressure-Volume (PV) loop provides valuable information about the cardiac energetics, particularly regarding how ventricular-arterial coupling defines ventricular performance in physiological and pathophysiological states. In a recent work, the simultaneous interaction between LV and Systemic Arterial Tree (SAT) PV-loops was exposed, as a novel framework of arterial-ventricular interaction. The enclosed area of the SAT PV-loop is associated with an energy dissipating phenomenon (not all the work done by pressure is recovered), due to the viscous role of smooth muscle vasomotor tone throughout the entire vascular network. Since it was demonstrated that energy dissipation during the conversion of cardiac pulsatile energy into arterial elastic energy is enhanced in trained athletes, as the higher cardiac pulsatile energy induced by training leads to functional and histological adaptations, the main objective of this work was to obtain a 'global arterial viscous modulus' from the analysis of SAT PV-loop, through the application of computational lumped (0D) and distributed (1D) blood flow models.