Some tachycardias are very brief or mild and do not pose a serious threat. Others require long-term treatment, and some are life-threatening. The treatment depends on the type of arrhythmia disorder — its frequency, duration, symptoms, and associated risks. Treatment decisions should also take into account any underlying heart conditions.
In very severe and life-threatening arrhythmias, emergency treatment to restore normal rhythm immediately may be done via electrical cardioversion from a defibrillator or through the use of intravenous drugs.