Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a type of cardiac arrhythmia that occurs in people with a structurally normal heart. Stress or anxiety-induced release of endogenous catecholamines causes a dysfunction in the myocytic calcium-ion channel, leading to ventricular arrhythmias that can cause dizziness, syncope, or sudden cardiac death.