Indications for a more careful evaluation:
(1) family history of sudden death or syncope
(2) structural heart disease
(3) cardiac arrhythmia
(4) recurrent episodes without good explanation
(5) falling with injuries
Potentially serious causes of exertional syncope may include:
(1) cardiac amyloidosis
(2) anomalous origin of a coronary artery
(3) atrial myxoma
(4) aortic valve disease
(5) long QT syndrome
(6) atrioventicular block
(7) catecholaminergic polymorphic ventricular tachycardia
(8) autonomic failure (Guillain-Barre syndrome, etc)
(9) hypertrophic cardiomyopathy
If no cause is found during the initial evaluation then exercise testing may be helpful but care must be taken that resources for immediate resuscitation and fall protection are present.
