Effect of visco-elastic damping and capillary bed model on the peripheral pressure wave

The visco-elastic models of Westerhof (1970), Wesseling (1973), Holenstein (1980) and Langewouters (1984) were incorporated in a linear distributed model of the arterial systemic circulation, extended with a pseudo nonlinear pressure-compliance function. Pressure and flow were computed at different locations along the arterial path. No significant damping was found for the proximal vessels, while more peripherally, the viscoelastic effect is considerable, reducing the pressure pulse at the femoral artery by about 20%. Except for those based on old species' data, all models revealed similar values. However, when changing the capillary bed model from a 3-element windkessel to a simple resistance, we found pressure pulse variations of the same order of magnitude (15-20% distal), even after compensating for the loss in compliance.