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Healtheuniversity > English > Cardiac College > Treat Heart Disease > Heart Medicines > Anti-arrhythmic medicines

Anti-arrhythmic medicines


  • Help fix irregular heartbeats
  • Reduce symptoms of irregular heartbeats (such as feeling your heart race or skip beats)
  • Help to control too fast, too slow, or irregular heartbeats
  • Lower the chance that you will have a stroke or develop heart failure


  1. Class 0: These medicines help by slowing down the fast electrical signals in your heart. They act on a part of your heart called the sino-atrial node.
  2. Class I: These medicines help by slowing down the fast electrical signals in your heart.
  3. Class II: These medicines are like brakes for your heart. They slow it down and make it beat less forcefully.
  4. Class III: These medicines help your heart's electrical signals stay in rhythm for longer.
  5. Class IV: These medicines work by calming your heart's electrical activity.

Potential Side Effects

  • Constipation (hard to poo)
  • Dizziness
  • Skin changes (such as red or dry skin)
  • Low blood pressure
  • Headache
  • Nausea
  • Ringing in your ears (tinnitus)
  • Sensitivity to the sun
  • Swelling from fluid buildup (edema)
  • Trouble peeing
  • Vision changes
  • Worsening of asthma

Note: The types of side effects will vary depending on which anti-arrhythmic medicine you are taking.

Common Names

  • Amiodarone (Class III)
  • Bisoprolol (Class II)
  • Diltiazem (Class IV)
  • Ivabradine (Class 0)
  • Metoprolol (Class II)
  • Procainamide (Class I)
  • Sotalol (Class III)
  • Verapamil (Class IV)

Ivabradine is the only Class 0 antiarrhythmic medicine. See below for details about this medicine.

  • Benefits
    • Helps people who have heart failure live longer and feel better
    • Lowers the need to be hospitalized to treat heart failure
  • Action
    • Ivabradine slows your heart rate. This medicine targets the natural pacemaker in your heart (the sinus node) to cause it to send signals more slowly.
  • Potential side effects
    • Dizziness or feeling lightheaded
    • Feeling fatigued or tired
  • Common names
    • Lancora


Your doctor will choose the right medicine for you based on what is causing your heart problem and how your body responds to the medicine. Always follow your doctor's advice and tell them if you have any side effects.

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