Carotid artery stenosis a physician detects a carotid bruit, or murmur, over the carotid artery by listening through a stethoscope during a physical exam. For people with symptoms, the American Heart Association recommends initial screening using ultrasound (see diagnosis below). Carotid artery stenosis is usually diagnosed by color flow duplex ultrasound scan of the carotid arteries in the neck. This involves no radiation, no needles and no contrast agents that may cause allergic reactions. This test has good sensitivity and specificity. Typically duplex ultrasound scan is the only investigation required for decision making in carotid stenosis as it is widely available and rapidly
Carotid body central chemoreceptors in the medulla oblongata that are primarily sensitive to changes in pH and P (a decrease in pH and an increase in P). The carotid body chemoreceptors are also sensitive to pH and P, but only secondarily. More specifically, the sensitivity of carotid body chemoreceptors to decreased P is greater when pH is decreased and P is increased. The output of the carotid bodies is low at an oxygen partial pressure above about 100mmHg (13,3 kPa) (at normal physiological pH), but below 60mmHg the activity of the type I (glomus) cells increases rapidly due to a decrease in