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What is Pacemaker?

Pacemakers are a type of Cardiovascular Implantable Electronic Device (CIED) used to treat arrhythmias, also known as heart rhythm disorders. This is done by keeping your heart beating steadily using electrical impulses sent directly to the lower chambers of the heart. The electric shock helps correct any irregularities or abnormalities in the heartbeat.

Who would need a pacemaker?

Pacemakers are prescribed to patients whose heart beats too slowly or irregularly, affecting the heart’s ability to pump blood efficiently throughout the body. Some heart rhythm problems include:

  • Bradycardia — where the sinus node causes the heart to beat too slowly.
  • Heart block — an occurrence where electrical impulses are delayed or blocked after leaving the SA node. 
  • Atrial fibrillation (AF) — a condition where the heart beats chaotically, alternating between heartbeats that are too fast or too slow.
  • Heart failure — a condition where the heart is unable to pump blood efficiently to the rest of the body.
How does a pacemaker work?

There are generally three parts to a pacemaker — a pulse generator, leads, and an electrode on each lead. As its name suggests, the pulse generator conducts electrical impulses to the heart via the lead, which touches the heart wall. 

The pacemaker will not send electrical impulses unless the heart’s rate falls below the device’s programmed limit.

Dual Chamber Pacemaker

Dual Chamber Pace Maker

A dual-chamber pacemaker is a type of cardiac pacemaker that is designed to regulate the rhythm of the heart using two leads, one placed in the right atrium (the upper chamber of the heart) and the other in the right ventricle (the lower chamber of the heart).

Dual-chamber pacemakers are programmed to regulate the pace of contractions of both chambers. This type of pacemaker helps the two chambers work together, contracting and relaxing in the proper rhythm, which can allow a heart rhythm that more naturally resembles the normal activities of the heart.

Leadless Pacemaker 

Image of Micra leadless pacemaker, taken from Medtronic

Advancements in technology have brought about the leadless pacemaker which does not require lead and, is instead, implanted directly into the heart using a catheter. This type of pacemaker can be used for single-chamber pacing; in patients with certain types of bradycardia.

What happens during a pacemaker insertion procedure?

A pacemaker insertion is considered a minor surgery and you will be admitted for 1 to 2 days. Large electrode pads will be placed on your chest to monitor your heart and you will be administered a sedative and antibiotic intravenously. 

  1. An incision near the collarbone is made and the leads (insulated wires) are inserted through your vein and towards the heart via X-ray imaging.
  2. The other ends of the leads are connected to the pulse generator, which is implanted in a small pocket under the skin in the lower abdomen.
  3. After insertion, a chest X-ray will be done to check the lungs and the position of the device and leads. Your cardiologist will also ensure that your pacemaker is working properly. 

Before your procedure, the pacemaker is programmed by your cardiologist and routine blood tests and other diagnostic imaging tests are carried out.

Do pacemakers need to be replaced?

Pacemakers generally last anywhere between 5 to 15 years, depending on the type of pacemaker and how often the patient needs them. Your cardiologist will advise you during follow-up consultations when your pacemaker will need to be replaced. However, other signs to look out for include:

  • Pain, swelling or redness at the implant site.
  • A persistent twitching sensation in your abdomen or chest.
  • A persistent feeling of heart flutters.
  • Pacemaker malfunction.
What’s the difference between a pacemaker and a defibrillator?

A defibrillator, or an implantable cardioverter-defibrillator (ICD), works similarly in keeping your heart beating steadily. One key difference is that it helps prevent cardiac arrest by inducing a life-saving shock to the heart if it detects a dangerous heart rhythm.


Such varied types of arrhythmias and heartbeat irregularities mean a variety of treatment options that take the form of different types of pacemakers. Your cardiologist will advise you on what pacemaker would best suit your condition

How can we help you?

We offer consultation for a comprehensive range of cardiac diagnostic tests and treatment plans.

Dr Joshua Loh

Senior Consultant Interventional Cardiologist

Medical Director at Capital Heart Centre, Dr Joshua Loh has more than 15 years of experience in the field of cardiology.

He has extensive experience in the treatment of complex coronary and interventional procedures.