What is syncope?

Syncope is the brief loss of consciousness (often accompanied by falling) due to transient decreased blood flow to the brain. 

What causes syncope?

The most common cause of syncope is “vaso-vagal” syncope; a benign condition that can happen to any healthy person if the circumstances present.  Vaso-vagal syncope is caused by a sudden surge in adrenaline, such as fear at the sight of blood, or anxiety at receiving good or bad news.  Vaso-vagal syncope can also occur when a person is relatively dehydrated.  This type of syncope is usually preceded by premonitory symptoms such as light-headedness, nausea, or diaphoresis (sweating). Other stimuli include coughing forcefully, turning the neck or wearing a tight collar (carotid sinus hypersensitivity), or urinating (micturition syncope).

Syncope can also be caused by serious underlying medical problems related to the:

Heart:  Cardiac arrhythmias, either rapid fast arrhythmias or markedly slow heart rates, can be a life threatening cause of syncope. 

Brain:seizure, stroke, transient ischemic attack (TIA).

Miscellaneous causes:  metabolic abnormalities, diabetes, pregnancy, and anemia. 

Autonomic Nervous System:  Orthostatic or postural hypotension: when a patient with this condition stands, the blood vessels in the lower extremities do not constrict normally causing blood to pool in the legs; blood pressure drops quickly and there is not adequate blood flow to the brain.  It is a common cause of syncope in the elderly.

What should I do if I have Syncope?

All patients with syncope should be evaluated by a doctor with expertise in this field.  Cardiac electrophysiologists are experts in the diagnosis and treatment of most causes of syncope.

The syncope evaluation begins with a careful review of the medical history and a physical exam. The doctor will ask detailed questions about premonitory symptoms, symptoms during syncope episodes, and the circumstances in which syncope occurred.

In about one-third of cases, the cause of syncope is never found.

Additional tests that may be ordered in the work-up of syncope are:

EKGto look for conduction disturbances or other cardiac conditions, Echocardiogram (ultrasound of the heart) to look for underlying structural heart disease,

Tilt table test, Electrophysiology studies, Holter monitoring, Autonomic nervous system testing, Neurological evaluation, Computed tomography scan

How is syncope treated?

When the cause is benign, patients can sometimes learn to avoid syncopal events by using “behavioral modification”.  By recognizing the prodromal symptoms that precede syncope, patients can adjust their behaviors (sit down or lie down) and avoid the syncopal episodes.  Medications can also be prescribed to treat benign causes of syncope. 

Wearing support garments or compression stockings to improve circulation can be used to treat orthostatic hypotension.

When the underlying cause is cardiac or neurologic, physicians can usually prescribe medications or implant pacemakers or implanted cardioverter-defibrillators to treat the underlying cause.

With the proper diagnosis and treatment, syncope can be managed and controlled. It is important to have a thorough evaluation by a physician. 

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