What is Pacemaker? Different types of pacemakers / How does it work?

How Do Pacemakers Work?

The heart has its own natural electrical system that regulates the heartbeat, with electrical impulses causing the heart muscles to contract rhythmically and pump blood. As a result of damage to the heart muscle resulting from a heart attack, aging, genetic defects or certain medications, heart rhythm abnormalities can develop over time. An implanted cardiac pacemaker can then be used to correct the abnormality. A pacemaker will then function as a backup or substitute for the natural electrical system. It contains two parts, which include:

• Pulse generator – This component houses the battery and electronic circuitry that sends electrical pulses to the heart.
• Leads – There can be one or more leads, which are small insulated wires that carry electrical signals from the pulse generator to the heart.

Pacemakers don’t generate impulses at all times, but work as a backup in most cases. In cases of bradycardia or a slow heartbeat, the pacemaker can then send impulses to rectify the heartbeat. In addition to tracking your heartbeat, newer pacemakers are even capable of sensing body movements and breathing rate and can accordingly calibrate the optimal heart rate.

Different Types of Pacemakers

Your cardiologist will make recommendations for the type of pacemaker depending on the condition that requires treatment. These could include any of the following:

• Single chamber pacemaker – Typically, a single chamber pacemaker has just one lead that is placed within the lower chamber. It is mainly used to send impulses to the right ventricle of the heart.
• Dual chamber pacemaker – As the name suggests, a dual chamber pacemaker contains two leads that are placed in the right atrium and right ventricle. They send synchronized impulses to mimic the sequential timing of contractions between the chambers.
• Biventricular pacemaker – This type of pacemaker may have two to three leads that are placed in the right atrium and ventricle, as well as in the left ventricle. Biventricular pacing is also described as cardiac resynchronization therapy and is used as a treatment for heart failure.
• Living with a Pacemaker – A pacemaker is surgically implanted and programmed to match the unique needs of each patient. In most cases, your doctor will also be able to check it remotely, as the device can transmit and receive information, such as your heart rate and rhythm, as well as information on the device battery. Although there is little to no risk of the device malfunctioning because of electrical interference, it is advisable to take some precautions. These include:
  • Keep your cellphone at least half a foot distance away from the pacemaker. This means that it should never be kept in your shirt pocket. Also, try to hold it to the opposite side ear.
  • Simply passing through metal detecting security systems like those at airports will not affect pacemaker performance. However, it is advisable to limit time spent in proximity to such devices.
  • Make sure that all health care providers are informed about your pacemaker as medical equipment and procedures like MRIs, CT scans, and shock wave lithotripsy can interfere with the pacemaker.

Make it a point to maintain a safe distance of at least two feet from any kind of power generating equipment, such as high voltage transformers or power generators. Most household appliances pose no risk to pacemakers, but if you’re still worried, check with your doctor.

Dr Rajeev Garg

MBBS, MD(Med), DNB (Cardio), Dip. Card (NIMS) MNAMS, FSCAI, FESC

Senior Consultant – Interventional Cardiologist

Disclaimer:The views and opinions expressed in this article belong solely to the author. They do not reflect the opinions or views of the organization.