Rare genetic cause of syncope or sudden death in young patients
Caused by defect in genes involved in intracellular calcium regulation
Untreated, mortality as high as 35% by age 30
Structurally normal heart
Catecholaminergic polymorphic ventricular tachycardia
Seizure
Idiopathic fascicular left ventricular tachycardia
Toxicologic exposure 
Wandering atrial pacemaker
CO poisoning 
Polymorphic ventricular tachycardia
Breath-holding spell