What is it?
Syncope is a medical term for fainting or blackouts. There are many causes of blackouts. The most common type is called vasovagal syncope. Most episodes occur while standing and occasionally while sitting but it almost never occurs when lying down. Many people describe feeling very warm and sweaty before blacking out.
Vasovagal syncope is not a serious or life threatening condition. It happens as a result of a drop in blood pressure leading to decreased blood flow to the brain causing dizziness or fainting. It can be serious on the rare occasion if it happens to you while driving!
Other causes of blackouts include an abnormal heart rhythm, either too fast or too slow, and seizures.
Tests We Do
An echocardiogram (heart ultrasound) is often performed to assess the structure of the heart. Tilt testing is sometimes performed to try to reproduce an episode of vasovagal syncope. While the blood pressure and heart rate are monitored, the patient is tilted up to 80 degrees (almost standing) to try to trigger an episode. This test, if positive, may make you feel light headed or nauseated.
Another test involves having you wear a 24 or 48 hour Holter monitor. This is a small tape recorder that you would wear with a strap on your waist to record your heart beats. Longer term monitoring is used to look for infrequent rhythm problems in select patients with an external or implanted loop recorder.
The most important treatment for vasovagal syncope is simply a change in lifestyle, which significantly improves most patients. These measures include drinking more fluids (2-3 liters per day), eating more salt, avoiding those things that trigger attacks and isometric exercise. A number of medications can be tried, but there is little proof that these are helpful. Very rarely pacemakers are required.
Other causes of blackouts are treated depending on the discovered cause.
There is very little risk involved in a tilt test. You are carefully monitored and have highly qualified doctors and nurses at your side at all times.