Antiarytmika

Antiarytmika, or antiarrhythmic drugs, are medications used to treat abnormal heart rhythms by altering the electrical activity of the heart. Their aim is to restore normal sinus rhythm or to control heart rate and prevent recurrence of arrhythmias in conditions such as atrial fibrillation, atrial flutter, ventricular tachycardia, and other supraventricular or ventricular tachyarrhythmias.

Most commonly, antiarrhythmics are categorized by the Vaughan Williams classification into four main classes: Class I (sodium channel blockers), Class II (beta-adrenergic blockers), Class III (potassium channel blockers), and Class IV (calcium channel blockers). Some drugs do not fit neatly into a single class or have multiple actions.

Representative agents include Class I: lidocaine and flecainide; Class II: metoprolol and propranolol; Class III: amiodarone, sotalol, dofetilide, and ibutilide; Class IV: verapamil and diltiazem. Other agents used in specific settings include digoxin, adenosine, and magnesium sulfate for particular arrhythmias or acute episodes.

Clinical use requires careful patient selection and monitoring. Antiarrhythmics can modify conduction, refractoriness, and automaticity, but they may also prolong the QT interval and provoke proarrhythmia or hemodynamic instability. They are typically prescribed after consideration of the rhythm type, comorbidities, and potential drug interactions, often with in-hospital initiation and ECG follow-up.

Adverse effects and cautions vary by drug. Amiodarone, for example, has a broad safety profile but can cause thyroid, liver, or pulmonary toxicity with long-term use. Others may cause bradycardia, heart block, hypotension, or torsades de pointes in predisposed individuals.