Perspective:

The following are 10 points to remember from this review of syncope:

1. Outcomes in patients with syncope are more a function of the severity of the underlying heart disease than of the severity of the syncopal episode.

2. Reflex (neurocardiogenic) syncope is the most common etiology of syncope, accounting for approximately two-thirds of cases.

3. Historical features (setting, triggers, and classic prodromal and residual symptoms) often are sufficient to establish a diagnosis of reflex syncope.

4. High-risk criteria that indicate the need for immediate hospitalization after an episode of syncope include heart failure or coronary artery disease, electrocardiographic abnormalities such as nonsustained ventricular tachycardia, a long QT interval, or bifascicular block, syncope during exertion or while supine, and electrolyte abnormalities.

5. When high-risk factors are absent, the risk of a life-threatening event is low and outpatient evaluation often is appropriate.

6. Tilt-table testing may be helpful when reflex syncope is suspected in the setting of an atypical presentation.

7. Exercise testing is indicated in patients with syncope during or shortly after exertion and in patients with chest pain suggestive of angina.

8. Electrophysiological testing is indicated when an arrhythmia is suspected, such as in patients with prior infarction or nondiagnostic sinus pauses or sinus bradycardia.

9. Implantable loop recorders are useful in patients who have infrequent episodes of unexplained syncope.

10. Specialized syncope centers and web-based interactive decision-making algorithms can improve the diagnostic yield and cost-effectiveness of syncope evaluations.