The rate of ventricular tachycardia can vary from 120-200 bpm. It is the rate of this arrhythmia that determines the severity of the condition. Ventricular tachycardia is the result of ectopic foci stimulating the ventricle, overwhelming it and causing the ventricle to beat out of control.
Ventricular tachycardia can be transient or it can be life threatening.
Even though the ventricles are contracting, it causes a reduction in ventricular filling as well as reducing cardiac output. It is the high rate of contraction that causes the reductions. Symptoms can range from syncope to myocardial ischemia or even infarction. This arrhythmia can be converted to normal sinus rhythm through a precordial thump or by defibrillation.