An introduction to pacemaker
- By Dr. Arijit Ghosh
When does someone need a pacemaker?
Most common indication of pacemaker implantation is cardiac arrhythmias. Different types of cardiac arrhythmias are as follows:
- Heart block - In this disorder, propagation of cardiac impulse from atrium to ventricle through atrioventricular (AV) node is delayed or absent.
- Atrial flutter and atrial fibrillation not controlled by medications - these conditions are associated with increased heart rate. If they are not controlled by medications then pacemaker implantation is advised.
Different diagnostic tests are available to diagnose cardiac arrhythmias.
It is the simplest of all tests. It is a painless test to detect cardiac arrhythmia. It also detects any organic heart disease.
Holter monitor records electrical activity of the heart for a period of 24 hours. During this period any event of cardiac arrhythmia is recorded.
In this procedure a thin flexible wire is passed through the vein of upper thigh or arm. The wire is used to detect electrical signals of the heart. Heart can also be stimulated to assess the electro-physiological pathway.
Introduction to pacemaker
The pacemaker looks like a matchbox and weighs between 20 to 50 g. It is reliable as well as comfortable. It is placed below the collarbone beneath the skin. The leads of the pacemaker are placed into the heart through a vein. The different types of pacemaker are as follows:
- Single chamber pacemaker – pacemaker with one lead.
- Dual chamber pacemaker - pacemaker with two leads.
- Biventricular pacemaker - pacemaker with three leads.
The sinus node of the heart is the natural pacemaker. It generates and propagates the electrical impulse of the heart. After successful implantation, the pacemaker takes over the role of sinus node and artificially generates impulses. Some pacemakers generate impulses at a fixed rate and some on demand basis.
Surgery and postoperative care
The pacemaker is implanted under local anesthesia with sedation. An incision is made to insert the pacemaker with its leads. The surgeon creates a pocket below the collarbone to lodge the pacemaker. Once the leads are placed, the tests are done to ensure proper functioning of the pacemaker. The final settings are done using a special device called a programmer.
The postoperative period is relatively shorter and uneventful. The patients are assessed for any possible complication and discharged from the hospital once recovery is ensured.
The patients with pacemaker can lead a normal healthy life. However, few precautions are warranted:
- Cell phones - Patients can talk on a cell phone, but the cell phone must not be placed over the pacemaker.
- Medical equipment - The patients with pacemaker must avoid medical procedures that involve exposure to electromagnetic energy. The procedures include MRI, radiation therapy, shock-wave lithotripsy etc.
- Security systems - Security systems like metal detector do not interfere with pacemaker, but patients must avoid lingering near a metal detection system. Individuals with pacemaker should carry an identity card stating that he or she is having a pacemaker.
- Power generating equipment - Patients with pacemaker must always stand at least two feet away from the welding equipment, transformers, generators, etc.
- Devices unlikely to interfere with pacemakers are microwave ovens, TV, remote controls, radios, etc.
With the above precautions patients with pacemaker can lead a normal healthy life. However, regular follow up and check is required for the proper functioning of the pacemaker. Rigorous or stressful physical activity is to be avoided by patients having a pacemaker installed. The patient should also be aware of the risks after the implantation such as blood clotting in the arm, pain, or pacemaker lead malfunctions and consult the cardiologist in case of any concern.