Nonneural beta-adrenergic vasodilating mechanism in temperature biofeedback.

Although finger temperature feedback has been used to produce digital vasodilation in normal persons and those with Raynaud's disease, the mechanism and site of this effect have not been studied. In the present investigation, feedback-induced vasodilation was attenuated by brachial artery infusions of propranolol in infused, but not contralateral, hands and was not affected by digital nerve blockade. Quantitative measurements of finger blood flow demonstrated that this vasodilation occurred in arteriovenous shunts in normal persons and in the finger capillary bed in those with Raynaud's disease. Raynaud's disease patients who received finger temperature feedback reported 80 fewer percent symptoms 1 and 2 years after treatment and retained the ability to increase finger temperature and capillary blood flow at these times. These effects were not shown by patients given autogenic training, a relaxation procedure.