New diagnostic modalities for the evaluation of the patient with syncope.

Syncope is a common clinical problem. Patients with cardiac syncope have a poor prognosis and a high incidence of sudden death during follow-up. The most common diagnosis in these patients is ventricular tachycardia in the setting of coronary artery disease. Patients with syncope and structural heart disease should undergo EP testing to exclude ventricular tachycardia. The use of SAE may be helpful in selecting patients who are likely to have ventricular tachycardia at EP testing. Patients with syncope and a normal heart have an excellent survival, but about 30 percent have recurrent spells. Those patients with a normal heart and syncope in the upright position often have neurally mediated syncope, and the diagnosis can be confirmed by tilt testing. Patients defying diagnosis should undergo loop monitoring to document the cardiac rhythm during syncope.