HEART HEALTH - Abnormal heart rhythms

Abnormal heart rhythms

An abnormal heart rhythm – sometimes called an arrhythmia – means your heart is beating too fast, too slow, or with an irregular pattern.

Your heart has an electrical system that tells it when to beat and push blood around the body.  If there is a problem with this system you may experience an abnormal heart rhythm.

How does the heart's electrical system work?

• The sinus node is a special group of cells in your heart, also known as your heart’s natural pacemaker.
• The sinus node sends an electrical signal to the chambers of your heart, which tells them when to contract and push blood through your heart.
• If your heart is working properly, the electrical signal will travel from the sinus node to the top chambers of your heart (atria) and then on to the lower chambers (ventricles).
• The normal electrical pattern of your heart is known as sinus rhythm. A normal sinus rhythm will generally cause your heart to beat between 60 to 100 beats per minute (bpm) when you’re resting.

My heart rate sometimes feels different. Is this a problem?

It's normal for your heart to beat at different rates during the day. It will be slower when you're at rest but may be faster when you are physically active such as when you are gardening, walking briskly, or running. Your heart rate might also be faster if you are anxious or excited.

You may experience a sensation of feeling your heart beating whether it is beating normally, quickly, slowly or irregularly. Some people describe them as feeling that your heart is pounding or fluttering. These sensations are called palpitations.  For most people, although palpitations can feel unpleasant, they’re usually harmless and do not mean anything is wrong with your heart.

You might also feel that your heart has missed or 'skipped' a beat or there has been an extra beat. An extra beat is called an ectopic beat. Ectopic beats are very common and are usually harmless and do not need any treatment.

If you are concerned about palpitations or ectopic beats, you should speak to your doctor who will be able to do an ECG to assess your heart rate and the rhythm.

What are the different types of abnormal heart rhythm?

There are many different types of abnormal heart rhythm. What type you have depends on where in your heart the rhythm (electrical impulse) starts, and whether it causes your heart to beat too fast, or too slow. The most common abnormal rhythm is atrial fibrillation.

• Fast heart rhythms such as supraventricular tachycardia (SVT), inappropriate sinus tachycardia, atrial flutter, atrial fibrillation (AF), ventricular tachycardia (VT) and ventricular fibrillation (VF) are known as tachycardias.
• Slow heart rhythms such as AV heart block, bundle branch block and tachybrady syndrome are called bradycardias.

To find out more about these conditions and their treatment, download or order our booklet Heart rhythms.

What causes an abnormal heart rhythm or arrhythmia?

There are lots of reasons why you may have a different heart rhythm. Common reasons are:

• The electrical impulses are coming from another part of the heart and not the sinus node.
• The electrical impulses are coming from the sinus node, but going to the lower chambers of the heart by an unusual path.

What are the tests and treatments for abnormal heart rhythms?

Depending on your symptoms, your doctor might recommend that you undergo an ECG,echocardiogram or electrophysiological (EP) study to help diagnose an abnormal heart rhythm. 

Depending on the type of abnormal heart rhythm, your doctor may recommend using medication to stop, prevent or control it.  Alternatively, they might suggest suggest a procedure such ascardioversion or catheter ablation, or surgery to insert an implantable cardioverter defibrillator orpacemaker.

Source: British Heart Foundation