A pacemaker is a small battery-operated device that’s placed (implanted) in your chest under the skin to control your heartbeat. Average pacemakers weigh as little as 1 ounce (28 grams) and size as of matchbox.

 A pacemaker has two parts:

1. The generator contains the battery and the information to control the heartbeat.
2. One to three leads (wires)  that deliver electrical signals from  pulse generator to your heart

What are the different types of pacemaker?

Depending on your condition, you might need one of the following types of pacemakers.

1. Single chamber pacemaker: This type usually carries electrical impulses to the right ventricle of your heart.
2. Dual chamber pacemaker:  This type carries electrical impulses to the right ventricle and the right atrium of your heart to control contractions of the two chambers in coordinated way
3. Biventricular pacemaker (three leads pacemaker): Biventricular pacing, also called cardiac resynchronization therapy, is for people who have heart failure and underlying Left Bundle Branch Block (LBBB). This type of pacemaker stimulates both of the lower heart chambers (the right and left ventricles) simultaneously to make the heart to work more efficiently.

Specialized pacemakers:

1. Leadless Pacemaker – Self-contained device without connecting leads (wires) and generator
2. An Automatic Implantable Cardioverter Defibrillator (AICD) is similar to a pacemaker, in that it is a small self-contained metal box which holds a battery, circuitry, and wire electrodes. Also, like a pacemaker, the electrodes are passed down to the heart through the veins under your collarbone. It is used for patients with a high risk for sudden cardiac arrest.  The AICD continuously monitors your heartbeat and whenever heart produces dangerous or life threatening heart beats  , it  deliver a shock to heart to normalize the heart rhythm . AICD has pacemaker function in built. It comes in single chamber and dual chamber options similar to normal pacemaker
3. CRT-D / COMBO Device: It is a Combination of Biventricular Pacemaker (CRT) and AICD . It is implanted in patients having indication of biventricular pacemaker (CRT) and who are at high risk for sudden cardiac arrest.

NB : Most of the above pacemakers come in two variants (MRI compatible or Non – MRI compatible)

How does a pacemaker work?

Electrical impulses are sent by the pacemaker device to tell your heart to contract and produce a heartbeat. Most pacemakers work just when they’re needed – on demand. Some pacemakers send out impulses all of the time

Your doctor will talk to you about which type of pacemaker is most suitable for you, which will depend on the reasons why you need to have one.

Why do you need a pacemaker?

You need a pacemaker if your heart is pumping too quickly or slowly (heart block ). In either case, your body doesn’t get enough blood. This can cause:

1. Fainting
2. Near fainting
3. Dizziness
4. Lack of energy
5. Fatigue
6. Shortness of breath
7. Exercise intolerance

How is pacemaker surgery performed?

Implanting a pacemaker typically takes one to two hours. You’ll receive aa local anaesthesia to numb the incision site. You’ll be awake and talking during the procedure.

Your cardiologist / surgeon will make a small incision below the collar bone. They’ll guide a small wire through the incision into a major vein near your collarbone. Then the surgeon will lead the wire / lead through vein to your heart. An X-ray machine / Fluoroscopy will help guide your surgeon through the process.

Using the wire (lead), your surgeon will attach an electrode to your heart’s right ventricle and another in right atrium. The other end of the wires (Leads) attaches to a pulse generator. This contains the battery and electrical circuits.

If you’re getting a biventricular pacemaker, your surgeon will attach a third lead to the left ventricle. At the end, your surgeon will close your incision with stitches.

What are the complications associated with a pacemaker?

Every medical procedure has some risks. Most risks associated with a pacemaker are from the surgical installation. They include:

1. An allergic reaction to anaesthesia
2. Bleeding
3. Bruising
4. Damaged nerves or blood vessels
5. An infection at the site of the incision
6. A collapsed lung, which is rare
7. A punctured heart, which is also rare

Most complications are temporary. Life-altering complications are rare.