What you need to know about pacemakers

Pacemakers are medical devices that are designed to help regulate the rhythm of your heart by delivering electrical impulses that pace the heart. This can help manage slow, fast or abnormal rhythms. 

If you’ve been diagnosed with bradycardia, tachycardia, heart block or heart failure, your doctor may recommend that you’re fitted with a pacemaker. 

What is a pacemaker?

A pacemaker is a battery-powered device that’s usually made up of two parts: a small box called a pulse generator, which contains the battery and controls the electrical signals that are sent to the heart, and one to three leads that connect the pulse generator to different parts of the heart. 

The heart is made up of four chambers: two upper chambers (the left and right atria) and two lower chambers (the left and right ventricles). 

The pulse generator is usually implanted under the skin on the left side of your chest, and the leads can be attached to one, two or three chambers of your heart. 

How is a pacemaker fitted?

Fitting a pacemaker takes anything from 30 minutes to two hours (depending on the type of device being fitted). It is performed under sedation with a local anaesthetic as a day case, so you can usually go home on the same day as your operation. 

A small incision will be made into the skin on the left side of your chest. A puncture will be made into a vein to allow your surgeon to pass a catheter down towards your heart, through which the leads of your pacemaker will be passed. X-ray imaging will be used to help guide the leads down into your heart. 

Finally, the leads will be attached to the pulse generator, which will be implanted just under your skin on the left side of your chest, and your wound site stitched back together. 

Types of pacemakers

There are three types of pacemakers, as follows:

  • Single-chamber pacemakers, which have one lead connected to the right atrium or right ventricle
  • Dual-chamber pacemakers, which have two leads connected to the right atrium and right ventricle
  • Biventricular pacemakers, which have three leads connected to the right atrium, right ventricle and left ventricle 

If you have bradycardia or heart block, usually a single- or dual-chamber pacemaker will be fitted to pace and sense your heart. Sensing refers to a pacemaker sensing the electrical activity of your heart. If it can’t sense normal electrical activity of your heart, it will pace the heart ie provide electrical stimulation to regulate its rhythm. 

If you have heart failure, you may need to have a biventricular pacemaker fitted. This is because in heart failure, the left and right sides of the heart don’t contract together. A biventricular pacemaker helps resynchronise the left and right sides so that they do contract together allowing the heart to pump more effectively. 


Implantable cardiac defibrillators are similar to pacemakers but usually larger. They can deliver a life-saving electrical impulse in the case of a cardiac arrest or life-threatening arrhythmia.

A cardiac defibrillator can be implanted on the left-hand side of your chest, with the leads passing through a vein down into your heart. Alternatively, it can be implanted on the side of your chest with the leads passing outside of the veins (subcutaneously) across your ribcage. 

There are different benefits to each type of cardiac defibrillator, which your doctor will explain to you.

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Recovering from your pacemaker surgery

In most cases, you can return home on the same day as your operation, or if your operation was later in the day, you may need to stay overnight. 

Once home, you will need to keep your wound site dry for seven to 10 days. Your stitches will dissolve over time. The pacemaker leads themselves are secured to your pectoral muscle on the left side of your body, so you will need to be careful not to make any large movements with your left arm for four to six weeks. 

If you have a pacemaker fitted, you won’t be able to drive for a week. If you have a defibrillator fitted, you won’t be able to drive for a month. 

You can take over-the-counter paracetamol to manage your pain and will have an outpatient appointment to check on your recovery after four to six weeks. 

You will also be given a special computer to keep at home, to which your pacemaker will communicate via WiFi. This will allow your doctor to remotely monitor your pacemaker. 

When and how are pacemakers replaced?

Most pacemakers last 10 to 12 years, after which they need their battery replaced. Exactly how long they last depends on how much they need to be used. 

Fitting a new battery is a simple procedure performed under sedation with local anaesthetic. It usually takes around 20 minutes. 

A small incision is made where the original incision to fit your pacemaker was made. The leads stay in place, the old pulse generator is disconnected and removed, and a new one is implanted and connected. 

Author biography

Dr Matthew Kahn is a Consultant Cardiologist at Spire Manchester Hospital, Spire Kenmore Clinic and the NHS Liverpool Heart and Chest Hospital. He is the Cheshire and Mersey Network Lead for Heart Failure and Complex Devices, and our local Heart Failure and pacemaker specialist at Spire Healthcare. He has a special interest in heart failure and complex pacing and defibrillator implantation. He is accredited by the European Heart Rhythm Association and holds a PhD from the University of Leeds. You can find out more about Dr Kahn on his website.

We hope you've found this article useful, however, it cannot be a substitute for a consultation with a specialist

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