Results when rate of an ectopic ventricular pacemaker exceeds sinus node
Usually benign,self limiting
Terminology<unk><unk> : 20-40 bpm<unk> : 40-120 bpm
Ventricular tachycardia: >120 bpm<unk><unk> : 20-40 bpm<unk> : 40-120 bpm
Ventricular tachycardia: >120 bpm
Reperfusion phase of acute myocardial infarction (most common cause)
Beta-sympathomimetics (isoprenaline or adrenaline)
Drug toxicity, especially digoxin, cocaine and volatile anaesthetics such as desflurane
Electrolyte abnormalities
Cardiomyopathy
congenital heart disease
myocarditis
Return of spontaneous circulation (ROSC) following cardiac arrest
Athletic heart
Accelerated idioventricular rhythm
Assume any wide-complex tachycardia is ventricular tachycardia until proven otherwise 
Wide-complex tachycardia
Regular
Wandering atrial pacemaker
Monomorphic ventricular tachycardia
Narrow-complex tachycardia
PSVT with aberrant conduction: