Monomorphic VT: Single abnormal focus or reentrant pathway and thus regular, identical-appearing QRS complexes Polymorphic VT: Several different foci or pathways and thus irregular, varying QRS complexes Nonsustained VT: Lasts < 30 seconds Sustained VT: Lasts ≥ 30 seconds or is terminated sooner because of hemodynamic collapse Catecholaminergic polymorphic ventricular tachycardia is a genetic disorder affecting intracellular calcium regulation in cardiac tissue.