Syncope

What is syncope?

Syncope is characterized by a brief episode when you lose posture and consciousness. This is caused by a temporary decline in your brain’s blood flow. Following an episode of syncope, you normally regain consciousness, feeling alert immediately thereafter, although a short sense of confusion may linger briefly.

What causes syncope?

You may have an underlying medical condition, perhaps related to blood flow to your brain, your nervous system or your heart, that is causing your syncope. If blood does not circulate properly, or the autonomic nervous system does not work the way it should, changes in blood pressure and heart rate can cause fainting. Metabolic abnormalities and anemia may also cause syncope.

What are syncope’s signs and symptoms?

Common signs and symptoms include: light-headedness; an unexplained fall; dizziness; drowsiness; grogginess; fainting, especially immediately after exercising or having a meal; and sensing weakness or unsteadiness when standing. In many instances, premonitory (advanced warning) symptoms repeatedly precede syncope. Among these are nausea, light-headedness, and palpitations (heartbeats that seem to flutter in your chest). Often those who experience syncope learn to recognize those premonitory symptoms as warning signs and take steps to avoid losing consciousness. Elevating the legs, sitting down or lying quickly is often enough to stop the syncope.

Are there different types of syncope?

There are various types of syncope: vasovagal, situational, cardiac and neurologic. In about one-third of cases, the cause of syncope is unknown.

Vasovagal syncope is the most common type of syncope. This takes place when a sudden drop in your blood pressure reduces the flow of oxygen-rich blood to your brain. Gravity influences our blood flow. When we stand up, the force of gravity causes our blood to settle below our diaphragm in the lower part of our body. To counteract this, our heart and nervous system step in to maintain proper blood pressure. If there is a malfunction in these functions of the heart and nervous system when standing up, orthostatic hypotension and therefore syncope can occur. In this condition, normal constriction of the blood vessels fails to occur upon standing. This results in the blood pressure dropping swiftly as blood pools in the legs. Dehydration and certain medications can provoke syncope.

Another type of vasovagal syncope is called situational syncope which occurs only when specific circumstances stimulate certain nerves in an unusual way. Different events can trigger a neurological reflex of this nature. Included are: pain, hunger, fear, dehydration, anxiety, severe emotional stress, or using drugs or alcohol. Hyperventilation brought on by anxiety or panic can also bring on this type of syncope. Other triggers may include: harsh coughing; constriction of the throat or turning the neck; or urinating.

Cardiac syncope is characterized by loss of consciousness brought on by a blood vessel or heart conditions that inhibit the brain’s blood flow. Included among these conditions are: valve disease, heart failure, irregular heartbeats (arrhythmia); blood clot; obstructed blood flow in the blood vessels or heart; and aortic stenosis.

Neurologic syncope, loss of consciousness due to a neurological condition; specifically, these may include: stroke; a seizure; transient ischemic attack (TIA); or some other rare cause such as normal pressure hydrocephalus and migraines.

Is syncope dangerous?

Because syncope could be the sign of a more serious condition, it is important to seek treatment right away after a syncope episode occurs.

Is syncope a common condition?

At some point in life, syncope will affect 3.5 percent of women and 3 percent of men. More prevalent as we age, it occurs in at least 6 percent of those who reach over age 75. Syncope can occur at any age, either with or without any other medical conditions.

How is syncope diagnosed?

A number of tests can be performed to identify underlying causes of your syncope. Evaluation using a screening tilt table, nervous system testing, hemodynamic testing and blood volume determination is often conducted. Heart rate and blood pressure measurements, blood volume calculation, hemodynamic testing and autonomic reflex testing are also used to diagnose syncope.

How is syncope treated?

Syncope can be resolved in most patients with accurate diagnosis and appropriate treatment. Treatment to prevent a syncope recurrence depends on the results of your evaluation and any underlying cause of syncope that have been identified. Treatment may include: a new medications or revising your current medications; compression stockings or support garments to improve your circulation; dietary changes; extra care when making the transition from sitting to standing; increasing your head’s elevation while sleeping; and altering or avoiding situations or “triggers” which you know might bring on a syncope episode.

Other treatments include: pacemaker implantation; biofeedback training so that you can adjust a rapid heartbeat; and implantation of a cardiac defibrillator.