HP_0004758 (Effort-induced polymorphic ventricular tachycardia) is polymorphic ventricular arrhythmias of varying morphologythat do not exist under resting conditions but appear only upon physical exercise or catecholamine administration. Also known as: Catecholaminergic polymorphic ventricular tachycardia, Exercise-induced polymorphic ventricular tachycardia.