Class III Antiarrhythmics: Restoring Rhythm in Atrial Fibrillation

Class III antiarrhythmics are a group of medications used to manage and treat certain types of cardiac arrhythmias, which are abnormal heart rhythms. These drugs primarily target the electrical properties of the heart to restore normal rhythm and prevent further arrhythmias. Unlike some other classes of antiarrhythmic drugs, class III antiarrhythmics do not predominantly affect the speed of electrical impulses in the heart but primarily affect the duration of action potentials.
One of the most well-known and commonly used class III antiarrhythmics is amiodarone. Other drugs in this class include dofetilide, sotalol, and ibutilide.
Here are some key points about class III antiarrhythmics:
1. Mechanism of Action: Class III antiarrhythmics primarily work by prolonging the action potential duration in cardiac cells, particularly in the atria and ventricles. This prolongation helps prevent the reentry of electrical impulses that can lead to certain types of arrhythmias, such as atrial fibrillation or ventricular tachycardia.
2. Indications: These drugs are used to treat a range of cardiac arrhythmias, including atrial fibrillation, atrial flutter, ventricular tachycardia, and some forms of ventricular fibrillation. They may also be used for patients who have had certain types of cardiac surgery to prevent arrhythmias.
3. Amiodarone: Amiodarone is one of the most commonly prescribed class III antiarrhythmics. It is effective in treating various types of arrhythmias but is known for its potential for serious side effects and long-term use monitoring. It can affect multiple organ systems, including the lungs, thyroid, liver, and eyes.
4. Dofetilide: Dofetilide is primarily used for treating atrial fibrillation and atrial flutter. It requires careful dosing adjustments and monitoring of kidney function because it is eliminated by the kidneys.
5. Sotalol: Sotalol has both beta-blocking and class III antiarrhythmic properties. It is used to treat ventricular arrhythmias and atrial fibrillation. Like dofetilide, it requires careful dosing and monitoring.
6. Ibutilide: Ibutilide is often used for short-term treatment of atrial fibrillation or atrial flutter. It is typically administered in a hospital setting due to its potential to cause serious arrhythmias as a side effect.
7. Side Effects: Class III antiarrhythmics can have significant side effects, including proarrhythmia (the development of new or worsened arrhythmias), bradycardia (slow heart rate), and other cardiac and non-cardiac adverse effects. Regular monitoring of patients taking these medications is essential.
8. Individualized Treatment: The choice of which class III antiarrhythmic drug to use depends on the specific type of arrhythmia, the patient's overall health, and other factors. These medications are often prescribed after careful evaluation by a cardiologist.
It's important to note that the use of class III antiarrhythmics requires close monitoring by a healthcare professional due to their potential for serious side effects and interactions with other medications. Patients should always follow their healthcare provider's instructions when taking these drugs and report any unusual symptoms or side effects promptly.

[@USMLEpass]

Heart Sounds App: play.google.com/store/apps/details?id=usmle.pass.heartsounds

[@steph9772]

At 0:36, did you mean drug examples for Class III Anti-arrhythmics?

[@USMLEpass]

Yes. I meant to say "Class III"
Oops....

[@leo.girardi]

@@USMLEpass then edit...

[@lilaaissani5945]

the Dr at the ER prescribed me 400mg of Amiodarone when i could just have a cardioversion can i stop it its been a month that im taking 1pill a day i refused to take 2 pills /day is it ok if i stop it now

[@lilaaissani5945]

knowing all the side effects i rather stop it

[@adrianfox9099]

I was put on Amiodarone after a stroke over a year ago. It made my life hell and I suffered from loss of weight, hyperthyroidism that made me acutely anxious, and terrible digestive problems. I would advise anyone about to take it not to do so until they have every aspect of this drug explained to them by a competent cardiologist. (Such things as the fact it stays in your system for 6 months even if you stop taking it as it is a cumulative drug not excreted by liver or kidneys). There are plenty of alternatives which are almost equally effective for AF and this drug should be a last resort one in my view.

[@samarfayyad4281]

👌👍👍

[@Angel268201]

Probably one of the worse informative videos I’ve seen. Awful!

[@whatislove7252]

That's not nice to say.

[@elliottfireice4394]

You do one then if your gods gift 🎁