Syncope (medicine) - Diagnostic Approach

Diagnostic Approach

For people with uncomplicated syncope (without seizures and a normal neurological exam) computed tomography or MRI is not indicated.

A hemoglobin count may indicate anemia or blood loss. However, this has been shown to be useful in only about 5% of patients being evaluated for fainting.

An electrocardiogram (ECG) records the electrical activity of the heart. It is estimated that from 20%-50% of patients will have an abnormal ECG. However, while an ECG may identify conditions such as atrial fibrillation, heart block, or a new or old heart attack, it typically does not provide a definite diagnosis for the underlying cause for fainting.

Sometimes, a Holter monitor may be used. This is a portable ECG device that can record the wearer's heart rhythms during daily activities over an extended period of time. Since fainting usually does not occur upon command, a Holter monitor can provide a better understanding of the heart's activity during fainting episodes.

The Tilt table test is performed to elicit orthostatic syncope secondary to autonomic dysfunction (neurogenic).

For patients with more than two episodes of syncope and no diagnosis on “routine testing”, an insertable cardiac monitor might be used. It lasts 28–36 months. Smaller than a pack of gum, it is inserted just beneath the skin in the upper chest area. The procedure typically takes 15 to 20 minutes. Once inserted, the device continuously monitors the rate and rhythm of the heart. Upon waking from a “fainting” spell, the patient places a hand held pager size device called an Activator over the implanted device and simply presses a button. This information is stored and retrieved by their physician and some devices can be monitored remotely.