Arrhythmias are treated depending on the type, cause and how severe it is. Certain arrhythmias may increase the risk of complications such as stroke, heart failure and thus require treatment. Common treatments include lifestyle changes, anti-arrhythmic medications, pacemakers, cardioversion, implantable cardioverter defibrillator, catheter ablation therapy surgery e.t.c. Cardiac arrhythmias can be treated using medications classified into four groups, Class I A, B, C II, III and IV, using the Vaughan Williams classification which is based on the site and mechanisms of action of these drugs and also on the electrophysiological changes that they evoke.