Three or more ectopic foci within the<unk>  myocardium serve as the<unk> 
Rate is less than 100bpm (in contrast to MAT)
Is irregularly irregular therefore sometimes confused with<unk>  fibrillation and sinus arrhythmia
Wandering atrial pacemaker
Intrinsic cardiac or pulmonary disease
Polymorphic ventricular tachycardia
Metabolic derangements
Accelerated idioventricular rhythm
Drug toxicity 
Narrow-complex tachycardia
Idiopathic fascicular left ventricular tachycardia