EFFECTS OF EXERCISE INDUCED BRACHIAL AND CAROTID ARTERY VASCULAR RESPONSES IN NORMAL SUBJECTS

Abstract

Background: Brachial artery reactivity in response to ischemia hyperemia reflects endothelial health. Responses of brachial artery and carotid artery to a physiologic stimulus of exercise may be a novel method to assess vascular heatlh. Purpose: To compare brachial artery (BA) endothelium-dependent vasodilation to exercise induced vasodilation and to evaluate carotid artery (CA) responses to exercise in normal subjects. Methods: We evaluated BA vasodilation in response to arm ischemia induced by blood pressure cuff as well as supine bicycle exercise stress induced BA and CA responses in 13 healthy volunteers aged 30±8 years. Results: There was a 10°/.)+4% BA vasodilation in response to ischemia. This was associated with a decrease in forearm resistance and an increase in forearm blood flow. Exercise produced 6±6<Y«1 and 8±S% vasodilation of BA and CA respectively. No significant change in brachial artery blood flow measured by PW Doppler (98±S5 to 78±38 rnl/min, baseline vs. peak p=(UJ6, aerta=-ft±t9'%) or In CA: 6(00 lfow (4"ft±(t~(0 496±237 ml/min, baseline vs. peak p=O.7, delta=-6±21 %) occurred. Conclusion: Supine bicycle exercise produces BA and CA vasodilation, Assessment of BA and CA reactivity by ultrasound is a novel method for assessing vascular endothelial function.