ABSTRACT
A precipitous decrease in blood pressure may lead to inadequate cerebral perfusion, potentially causing reduced physical and/or mental capacity and syncope. The autonomic nervous system has a central role in the regulation of blood pressure. Blood pressure was measured non-invasively from a digital artery and stroke volume, cardiac output and total peripheral resistance were calculated according to the Modeflow technique and are presented as percentage changes from the supine position. Autonomic mediated syncope is regarded as the most common cause of intermittent and usually extremely short-lived autonomic cardiovascular dysfunction. The reduced partial pressure of oxygen of the cabin environment that occurs with ascent to altitude could also increase the risk of syncope. Syncope, when it occurs in an aviator, is often benign, but it warrants careful and individual consideration.
