Table 1

Classification of Ventricular Arrhythmias in the Absence of Structural Heart Disease

I. Non–life-threatening (typically monomorphic)
 A. Outflow tract
  Right ventricular outflow
  Left ventricular outflow
  Aortic sinus of Valsalva
  Peri His bundle
 B. Idiopathic left ventricular tachycardia
  Left posterior fascicle
  Left anterior fascicle
  High septal fascicle
 C. Other
  Mitral annulus
  Tricuspid annulus
  Papillary muscle
  Perivascular epicardial
II. Life-threatening (typically polymorphic)
 A. Genetic syndromes
  Long QT
  Catecholaminergic polymorphic ventricular tachycardia
  Short QT
 B. Idiopathic ventricular fibrillation