Antiarrhythmic medications are a varied class of treatments used to treat abnormal cardiac rhythms, or arrhythmias, caused by irregular electrical activity in the heart. These drugs try to restore a normal heart rhythm and prevent arrhythmia-related problems like fainting, stroke, or cardiac arrest. There are various types of antiarrhythmic medicines, each of which targets a distinct mechanism involved in the creation or propagation of aberrant electrical impulses in the heart. Class I antiarrhythmics, which are classified into three subclasses (Ia, Ib, and Ic), function by inhibiting sodium channels in cardiac cells. This blockage serves to maintain the cell membrane and slows the transmission of electrical impulses. Examples are procainamide (Ia), lidocaine (Ib), and flecainide (Ic). Class II antiarrhythmics are predominantly beta-blockers, which decrease adrenaline's impact on the heart. These medications inhibit the heart's response to stress hormones by inhibiting beta-adrenergic receptors, decreasing the heart rate and reducing its workload. Common examples include propranolol and metoprolol. Class III antiarrhythmics work largely by inhibiting potassium channels to prolong the duration of action potentials in cardiac cells. This action serves to keep the heart's electrical activity stable. Amiodarone and sotalol are popular Class III antiarrhythmics. Calcium channel blockers, which prevent calcium ions from entering heart cells, make up the majority of Class IV antiarrhythmics. As a result, they diminish the heart's contractility and pace. Verapamil and ditiazem are examples of Class IV antiarrhythmics. Aside from these primary classes, several medicines have mixed antiarrhythmic characteristics, targeting numerous ion channels or utilizing novel methods. In addition, newer medications or drug combinations may be employed depending on an individual's arrhythmia type and medical history. However, antiarrhythmic medications can have side effects and mix with other treatments, needing close monitoring and adjustment under the supervision of a healthcare practitioner. Common adverse effects include dizziness, exhaustion, and serious problems such proarrhythmia, in which the drug causes or intensifies arrhythmias. Antiarrhythmic therapy is chosen based on a number of parameters, including the kind and severity of the arrhythmia, overall health state, and the presence of other medical disorders, emphasizing the significance of tailored treatment programs and constant medical supervision.
