antiaritmiásszerek

Antiarrhythmics are a class of medications used to treat and prevent abnormal heart rhythms, known as arrhythmias. These drugs work by altering the electrical activity of the heart, thereby stabilizing its rhythm. They are broadly categorized into several classes based on their mechanism of action on the cardiac action potential and ion channels.

Class I antiarrhythmics, also known as sodium channel blockers, reduce the rate of sodium ion influx into cardiac cells, slowing conduction velocity. They are further subdivided into Class Ia, Ib, and Ic based on their potency and duration of action. Class II antiarrhythmics are beta-blockers, which reduce the effects of catecholamines on the heart, decreasing heart rate and contractility. Class III antiarrhythmics primarily prolong the repolarization phase of the cardiac action potential by blocking potassium channels. Class IV antiarrhythmics are calcium channel blockers, which reduce calcium influx into cardiac cells, slowing conduction through the AV node and decreasing heart rate.

The choice of antiarrhythmic medication depends on the specific type of arrhythmia, the patient's underlying cardiac condition, and potential side effects. Antiarrhythmics can have significant adverse effects, including proarrhythmia (inducing new or worsening existing arrhythmias), bradycardia, hypotension, and heart failure. Therefore, their use requires careful monitoring by a healthcare professional. They are prescribed to manage conditions such as atrial fibrillation, supraventricular tachycardia, and ventricular tachycardia.