The treatment of tachycardias will differ depending on the clinical tolerance and/or hemodynamic and amplitude of QRS. In case of instability will take place synchronized electrical cardioversion. In the narrow QRS tachycardia we will perform vagal maneuvers or manage adenosine providing information about the type of arrhythmia and thus choosing the most appropriate treatment. In the wide QRS tachycardia, if there are doubts about its origin, we will treat them as if they were of ventricular origin for their potential severity and mortality. The treatment of ventricular tachycardia differs if they are monomorphic or polymorphic and the triggering cause. The risk of bradycardia with asystole or hemodynamic compromise will be treated with drugs (atropine, dopamine, isoproterenol) and/or temporary transcutaneous or intravenous pacemaker.