Regional Cold Stress Leads to an Upforward Shift in the Whole Elastance Curve of Arterial Wall

The purpose of this study was to assess the time-dependent elastance of the radial arterial wall using a sinusoidal vibration method in room temperature and cold stress conditions. When a tiny sinusoidal displacement with varying frequencies is imposed on the superficial radial artery, its wall elastance can be derived from the reactive force of the wall, and the amplitude and frequency of the small displacement. The results showed in 20 healthy subjects that the 5-min cold stress with 4°C ice bags significantly increased the dynamic range of the radial wall elastance from 6.3±±2.3 ×10⁴ dyne/cm (at room temperature) to 9.2±±3.7 ×10⁴ dyne/cm (p<;0.05). In addition, peak elastance of the radial wall became significantly greater in the cold stress (5.82±±2.24 ×10⁵ dyne/cm) than at room temperature (3.86±±1.26 ×10⁵ dyne/cm) (p<;0.001). In summary, constriction of the radial artery in response to an external cold stress may lead to an up forward shift in the time-varying wall elastance curve.