Antiarytmisten

Antiarytmisten, or antiarrhythmic drugs, are medicines used to treat abnormal heart rhythms. They aim to restore normal rhythm or slow the heart rate in conditions such as atrial fibrillation, atrial flutter, supraventricular tachycardia, and ventricular tachycardia. Because they affect cardiac conduction, careful drug choice is needed based on the rhythm, heart structure, and other health issues.

Most are grouped by the Vaughan Williams classification into four main classes. Class I are sodium channel blockers that slow depolarization (examples include flecainide and propafenone; lidocaine is used for acute ventricular arrhythmias). Class II are beta-blockers (metoprolol, propranolol) that reduce AV nodal conduction. Class III are potassium channel blockers (amiodarone, sotalol, dofetilide, ibutilide) that prolong repolarization. Class IV are calcium channel blockers (verapamil, diltiazem) that slow AV nodal conduction. Some drugs, notably amiodarone, have multiple actions and do not fit neatly into a single class.

Because antiarrhythmics can be proarrhythmic, their risks must be weighed against benefits. They interact with other medications and electrolyte disturbances, and some have organ toxicities (for example, amiodarone can affect thyroid, liver, and lungs). Choice depends on arrhythmia type, left ventricular function, and the goal of therapy (rhythm vs rate control).

Monitoring includes regular ECGs to assess rhythm and QT interval, plus blood tests for electrolytes and organ function as needed. In some patients, catheter ablation or device therapies may be preferred to long-term drug treatment.