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Heart Disease Health Center

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When Your Heart Rhythm Isn't Normal

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"Arrhythmia" means your heartbeat is irregular. It doesn't necessarily mean your heart is beating too fast or too slow. It just means it's out of its normal rhythm.

It may feel like your heart skipped a beat, added a beat, is "fluttering," or is beating too fast (which doctors call tachycardia) or too slow (called bradycardia). Or, you might not notice anything, since some arrhythmias are "silent."

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Arrhythmias can be an emergency, or they may be harmless. If you feel something unusual happening with your heartbeat, call 911 so doctors can find out why it's happening and what you need to do about it.

Causes and Types of of Arrhythmias

You could have an arrhythmia even if your heart is healthy. Or it could happen because you have:

The many types of arrhythmias include:

Premature atrial contractions. These are early extra beats that start in the heart's upper chambers, called the atria. They are harmless and generally don't need treatment.

Premature ventricular contractions (PVCs). These are among the most common arrhythmias. They're the "skipped heartbeat" we all occasionally feel. They can be related to stress or too much caffeine or nicotine. But sometimes, PVCs can be caused by heart disease or electrolyte imbalance. If you have a lot of PVCs, or symptoms linked to them, see a heart doctor (cardiologist).

Atrial fibrillation. This common irregular heart rhythm causes the upper chambers of the heart to contract abnormally.

Atrial flutter. This is an arrhythmia that's usually more organized and regular than atrial fibrillation. It happens most often in people with heart disease and in the first week after heart surgery. It often changes to atrial fibrillation.

Paroxysmal supraventricular tachycardia (PSVT). A rapid heart rate, usually with a regular rhythm, starting from above the heart's lower chambers, or ventricles. PSVT begins and ends suddenly.

Accessory pathway tachycardias. You can get a rapid heart rate because there is an extra pathway between the heart's upper and lower chambers. It's just like if there was an extra road on your way home as well as your usual route, so cars can move around faster. When that happens in your heart, it can cause a fast heart rhythm, which doctors call tachycardia. The impulses that control your heart rhythm travel around the heart very quickly, making it beat unusually fast.

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