What is a pacemaker and when is it used?

A pacemaker is a small, battery-operated medical device implanted under the skin, usually in the chest area, to help control heart rhythm when it beats too slowly or when there is a problem with the heart's natural electrical conduction system. The device does not treat all types of arrhythmias; rather, it is used primarily for conditions where the heart struggles to maintain a rate sufficient to pump blood efficiently to the body, a state clinically known as bradycardia or conduction disorders [1].

How does a pacemaker work?

The heart relies on electrical signals traveling from the sinus node (the heart's natural pacemaker) through specific pathways to reach the heart chambers, causing them to contract regularly. In certain conditions, the production of these signals may slow down, or a "block" may occur in their transmission pathway. A pacemaker continuously monitors the heart's electrical activity, and when it detects that the heart rate is below the programmed limit, it sends small, painless electrical impulses to stimulate the heart muscle to contract at the required normal rate [3]. [4].

Medical conditions requiring a pacemaker

Cardiologists usually recommend implanting a pacemaker when the heart's electrical system cannot regulate the pulse automatically. The most notable conditions requiring this intervention include:

• Bradycardia: A condition where the heart beats too slowly, leading to insufficient oxygenated blood reaching the brain and other organs, which may cause dizziness, fatigue, or shortness of breath [1].
• Sick Sinus Syndrome: Where the sinus node fails to control heartbeats properly, causing irregular slowing or failure of the heart to increase its rate during physical activity [3].
• Heart Block: This occurs when there is an impairment in the transmission of electrical signals between the atria and the ventricles. In cases of "complete" or third-degree heart block, signals stop reaching the ventricles entirely, making the device a vital necessity to maintain regular blood circulation [3].

How is the decision for implantation made?

The decision to implant a device is not routine; it depends on a careful clinical assessment. The doctor will first perform diagnostic tests, including an electrocardiogram (EKG) and a review of the patient's medical history and symptoms. In cases where no clear symptoms are present, the doctor may simply monitor the patient. However, if bradycardia causes symptoms such as recurring fainting, shortness of breath, or chest pain, surgical intervention to implant the device may become the safest therapeutic option to prevent serious complications [1]. To learn more about when irregular heartbeats become concerning, you can read about cardiac arrhythmias (Arabic).

Tips for living with a pacemaker

Once the device is implanted, the patient needs regular follow-ups with a cardiologist to ensure battery efficiency and the safety of the settings. Patients must always inform their doctors about the device before undergoing any medical examination or imaging, and they should avoid direct exposure to strong magnetic fields. If a patient experiences symptoms such as sudden shortness of breath, severe chest pain, or loss of consciousness, emergency medical care must be sought immediately, as these signs may indicate a malfunction in the device's electrical performance or a progression in the cardiac condition [1]. [5].

Medical references

• Arrhythmia
• Arrhythmias Conduction Disorders
• Pacemakers - How They Work | NHLBI, NIH
• Pacemakers - Living With a Pacemaker | NHLBI, NIH