A Primer on Syncope and the Syncope Center

What is syncope? What happens when you faint?

Syncope (pronounced "sin-ko-pea") is the medical term for fainting. Syncope is a sudden and transient loss of consciousness which has many causes. Ultimately most causes of syncope produce a dramatic fall in blood pressure which leads to fainting.

Is syncope common?

Nearly half of all Americans will experience at least one episode of syncope during their lifetime. Syncope occurs in people of all ages from young children to elderly patients. More than 100,000 patients per year present to a physician reporting repeated episodes of syncope. Syncope accounts for 3% of all emergency room visits and 1% of hospitalizations.

What causes syncope?

There are many causes of syncope. Some are due to significant heart disease, others are less serious. More than half result from a recognizable cardiovascular cause. Less commonly, syncope is caused by noncardiovascular disorders such as dehydration, a low blood sugar, a stroke, a seizure, or as part of a panic attack. In patients with heart disease, syncope often signals a mechanical or electrical problem. Mechanical causes of syncope include blockage of one of the heart valves or abnormalities in the way in which the heart muscle contracts. The electrical rhythm disturbances that cause syncope can be either very slow rhythms or very fast rhythms, both of which can be dangerous and require treatment. Syncope can also result from abnormalities of the reflexes that control heart rate and blood pressure.

Sometimes, the evaluation of a patient with syncope will point to a non-cardiovascular cause. In such a circumstance, the Syncope Center utilizes consultants from other specialties (such as endocrinology, neurology, psychiatry) who may direct the evaluation towards other types of diagnostic testing.

Can syncope be dangerous? Should everyone who faints see a doctor?

Regardless of the cause of syncope, anyone who loses consciousness is at risk for injury as a result of falling. Some patients with syncope have warning signs and are able to lie down before they lose consciousness completely. Other patients may not have warning signs and may hurt themselves by falling unexpectedly. Even if a patient has a benign cause of syncope, they may need treatment to protect them from the risk of losing consciousness recurrently. Because some types of syncope are serious, all patients with syncope should be evaluated by a doctor.

What types of diagnostic tests are done to determine the cause of syncope?

The evaluation of a patient with syncope begins with a history and a physical examination by a physician. If a dangerous cause is suspected, the patient should be admitted to the hospital until the precise cause is determined and treatment is begun. Most patients can have the evaluation as an outpatient.

Finding the cause of a patient's syncope can be simple. Most often, the patient's description of the faint, as well as his/her medical history can be enough to suggest the cause of syncope. Often, however, we have to use tests to determine the exact cause. Based on the history, the evaluation of a patient with syncope will be individually tailored to save time and expense. Since most patients have a cardio-vascular cause of syncope, diagnostic testing begins with an evaluation of the heart using tests which are known to identify the cause of syncope in large numbers of patients. The tests to be done and their sequences are carefully selected based on the patient's presentation starting with simple, non-invasive (and generally less expensive) tests. One or more of the following tests may be used:

Echocardiogram:

an echocardiogram makes ultrasound pictures of the heart to determine whether cardiac anatomy or pumping function is normal.

Electrocardiogram:

commonly known as an "ECG", is an illustration of the heart's electrical rhythm and may identify rhythm disturbances which may produce syncope.

Holter Recording:

is a continuous 24-hour recording of the electrocardio-gram. Patient's are connected to a few ECG leads; the ECG is then recorded on a special tape recorder the size of a Sony WALKMAN. This 24-hour recording of the heart's rhythm may identify transient disturbances in the rhythm which can cause syncope. Sometimes, we are lucky and obtain an actual recording of the patient's rhythm during an episode of lightheadedness or fainting!

Signal-averaged Electrocardiogram:

is a computer enhanced electrocardiogram which allows us to identify the circuits responsible for the fast rhythms that can cause syncope.

If these simple tests do not determine the cause of syncope, the approach to diagnostic testing shifts to tests that explore the cause of fainting in a controlled laboratory situation. Two types of test are used to provoke syncope; which test is done first is based on the results of the history and non-invasive tests that provide clues as to the cause of syncope.

Cardiac Electrophysiology Testing:

make precise measurements of the heart's electrical conduction system and determine the heart's vulnerability to developing either fast or slow rhythms which may cause syncope. They often reveal the cause of syncope in patient's who have structural heart disease and/or have electrical abnormalities detected on the signal-averaged electrocardiogram or the Holter recording. Electrophy-siology studies are remarkably well tolerated and require only local anesthesia for the placement of intravenous plastic coated wires called 'catheters'.

Tilt Table Testing:

involves lying on a table which is able to tilt upright. In some patients, this simple maneuver will reveal abnormal cardiovascular reflexes that produce syncope.

What types of therapy are used to treat fainting spells?

The treatment of a patient with syncope depends entirely on the cause. Every cause of syncope has an effective treatment, but given the large number of causes of syncope, there are a large number of different treatments. For example, therapy may be as simple as a change in diet or a daily medication. Some patients may require a pacemaker or surgery.

Who will treat my fainting spells?

After the cause of syncope has been established, a full report of the diagnostic findings will be sent to your private physician. A Syncope Center physician will discuss the therapeutic options with your physician who will discuss them with you. During the period after therapy is initiated, continued assistance is available through the Syncope center if requested by your primary physician.

To Get Further Information

For further information or to set up an appointment with a member of the Syncope Center, call 305-9466.