What is the function of the baroreflex?

What is the function of the baroreflex?

The baroreflex is the fastest mechanism to regulate acute blood pressure changes via controlling heart rate, contractility, and peripheral resistance. The baroreflex or baroreceptor sensitivity (BRS) index is a measurement to quantify how much control the baroreflex has on the heart rate.

What can damage baroreceptors?

Radiation is a common cause of baroreceptor damage. While neck irradiation is a well-recognized cause, intensive upper chest irradiation may have similar consequences due to damage to the baroreceptors in the aortic arch.

How is baroreflex failure treated?

However, baroreflex failure can result from surgery or radiation treatment for cancers of the neck, injury to the nerves involved in sensing blood pressure, or a degenerative neurologic disease. Treatment usually involves medications to control blood pressure and heart rate along with stress reduction techniques.

What happens if the baroreflex does not function well?

In baroreflex failure, there is loss of buffering ability, and wide excursions of pressure and heart rate occur. Such excursions may derive from endogenous factors such as stress or drowsiness, which result in quite high and quite low pressures, respectively.

What triggers the baroreflex?

There are many different ways to trigger a baroreflex response including carotid sinus massage or electrical stimulation of carotid sinus nerves, the Valsalva maneuver and head-up tilting, lower body negative pressure application, intravenous bolus injection of vasoactive agents, and other techniques [188].

How does HTN cause heart failure?

High blood pressure forces your heart to work harder to pump blood to the rest of your body. This causes part of your heart (left ventricle) to thicken. A thickened left ventricle increases your risk of heart attack, heart failure and sudden cardiac death. Heart failure.

What is autonomic failure syndrome?

Pure autonomic failure is dysfunction of many of the processes controlled by the autonomic nervous system, such as control of blood pressure. It is not fatal. Pure autonomic failure is caused by abnormal accumulation of synuclein in the brain.

Is baroreflex autonomic?

Baroreflex sensitivity (BRS) (also known as baroreflex gain) is used as a measure of autonomic control of the cardiovascular system. Generally, it is a measure of the autonomic effector response to a given change in arterial pressure.

What are the signs and symptoms of baroreflex failure?

Individuals may also have hypotension (low blood pressure) with normal or reduced heart rate during periods of rest. Symptoms of baroreflex failure may include headache, sweating, and a heart rate that does not respond to medications.

Why is the baroreflex not used for hypertension?

Previous versions: The baroreflex receives less attention nowadays because most students of hypertension are convinced that faulty volume regulation by the kidneys is responsible for long-term blood pressure increases.

How is clonidine used to treat baroreflex failure?

Therapy with clonidine reduced the frequency of attacks by 81 percent and attenuated the elevated blood pressure and heart rate in the attacks that occurred. The syndrome of baroreflex failure should be considered in patients with otherwise unexplained labile hypertension.

When to apply phenylephrine for baroreflex failure?

Intravenous bolus application of 50 μg phenylephrine at 0 seconds caused a rapid pressor response, reaching a maximum of >25 mm Hg above baseline after 30 to 40 seconds. Normally, the phenylephrine pressor response is associated with a baroreflex-mediated decrease in heart rate and MSNA.