Pacemaker – have you heard of this device before? Here I will discuss what it is, how it is implanted and what precautions you need to take if you have one.
The human heart beats at a rate of 60 to 100 beats per minute at a regular pace. At times, the heart can slow down to a rate that is lower than the normal. When this happens, patients may experience symptoms such as dizziness, breathlessness or lightheadedness. Some patients may even collapse.
Patients in whom the heart rate is too slow or irregular often require pacemakers. Here we will take a look at what pacemakers are.
What is a Pacemaker?
A pacemaker (sometimes called an artificial pacemaker) is a small device that measures around 1.5 inches in length (see picture above) that sits in a small pocket underneath the skin near the heart. It is a metallic device to which is attached one or two wireless called leads. These leads are placed in the chambers of the heart and the pacemaker controls the rate and rhythm of the heartbeat.
In other words, an electronic pacemaker contains two main parts:
- Pulse generator – This is a small oval metallic device that generates electrical impulses that are transmitted to the heart.
- Leads or electrodes – These are flexible insulated wires that are attached to the pulse generator and are inserted into the heart chambers. Up to 3 wires may be attached to the pulse generator. Electricity from the pulse generator is transmitted through these wires into the heart and this in turn controls the rate at which the heartbeats.
When are Pacemakers Inserted?
Pacemakers are inserted when the heartbeat is either too slow or is irregular. The use of the pacemaker is to maintain a normal and a regular heart rhythm.
Before we discuss why pacemakers are inserted, it may be worthwhile reviewing how electricity is conducted through the heart.
Below are some of the common reasons why pacemakers will be inserted:
- A slow and irregular heart rhythm such as slow atrial fibrillation
- An irregular heart rhythm that results in episodes of collapse or near collapse
- An irregular, slow heart rhythm that follows a heart attack (such as heart block)
- Advanced heart failure accompanied by life-threatening irregular heart rhythms such as ventricular tachycardia (here the pacemaker is often a part of a treatment system called an implantable cardioverter defibrillator or ICD).
- Irregular or slow heart rhythms due to heart failure
What are the Types of Pacemakers?
There are primarily three kinds of pacemakers –
1. Single chamber pacemaker
Here, a single wire i.e. lead is attached to the pacemaker pulse generator and is inserted into the heart. The wire is usually placed in the right ventricle.
2. Dual chamber pacemaker
Here, two leads that are attached to the pacemaker pulse generator are inserted into the heart. The first lead is inserted into the right ventricle while the second is often inserted into the right atrium.
3. Bi-ventricular pacemaker
This is a specialised pacemaker that is used in the treatment of patients who have advanced heart failure and in whom the normal electrical conduction is disrupted.
The pacemaker leads are inserted into both ventricles and the contraction of both the chambers is synchronized with the help of the pacemaker. For this reason, this treatment is sometimes called cardiac resynchronisation therapy or CRT.
This treatment can help improve the function of the heart and the way the heart contracts.
How are Pacemakers Implanted?
Pacemaker insertion is often performed under local anaesthesia. Depending on whether the individual is right handed or left-handed, the device is often placed in a pocket on the non-dominant side. What this means is that if an individual is right-handed, the pacemaker will be inserted on the left-hand side and vice versa.
Pacemaker insertion is performed with the individual awake and under local anaesthesia. If required, patients may request a small amount of sedation if they feel nervous.
The site where an incision is to be made is cleaned with antiseptic solution and the patient is covered in sterile drapes. local anaesthetic is injected into the skin and subcutaneous tissues.
A small incision of about 1 to 1.5 inches is made just under the collar bone near the shoulder joint. A pocket is created by separating out the tissues and a vein called the subclavian vein is located using a needle that is attached to a syringe filled with saltwater (normal saline).
Once this vein is located, a wire is passed into the vein and along this the required number of pacemaker leads are passed.
The procedure is performed under x-ray guidance so the doctor can visualise the heart and the leads at all times.
Once the cardiologist is satisfied that the leads are in place, the leads are sutured to the nearby tissues and the ends of the leads are attached to the pulse generator box. This box is then placed in a small pocket underneath the skin and tissues which are sutured close.
After the Procedure
Pacemaker implantation is performed as a day case procedure. Patients are admitted on the day of the procedure and are discharged the following day.
A chest x-ray may be performed the day after the procedure to confirm the position of the leads and to ensure that the pacemaker has not moved overnight.
Prior to discharge, a pacemaker check is conducted to check the battery, the position of the leads and the amount of electricity being passed through the leads. These pacemaker checks are performed from time to time for a number of years.
For a few days after insertion of the pacemaker, patients are advised not to lift anything heavy and to avoid strenuous exercise. The wound needs to heal adequately and a follow-up appointment may be arranged to ensure this has happened.
A small amount of bleeding or bruising at the site is common. Patients may experience some pain and this can be easily treated with painkillers.
Risks of Pacemaker Implantation
As mentioned above, some individuals may notice a small amount of bleeding and bruising at the site of the pacemaker implant. This often passes after a few days.
Any pain can be easily treated with over-the-counter medication such as Paracetamol (Dolo, Crocin) or Non-Steroidal Anti-Inflammatory Drugs ( Ibuprofen).
Rarely, an infection may occur at the site of the surgical incision. If this happens, it is essential that the patient to see the doctor for a complete assessment.
Minor infections can be treated with antibiotics where as deeper infections that have extended into the pocket may require surgical drainage.
Another rare complication that may occur during pacemaker insertion is accidental puncture of the lung.
As a needle is inserted into this subclavian vein (that lies under the collar bone and close to the lung), it is sometimes possible for the tip of the needle to damage the lining of the lung.
When this happens, a small amount of air may enter the space around the lung resulting in a condition called a pneumothorax. This pneumothorax can be easily detected on a chest x-ray.
If the pneumothorax is small, no treatment is required and the air gets absorbed by itself. However, if the pneumothorax is large, patients may require the insertion of a chest drain to remove the air through a tube.
Finally, another rare complication that may occur is puncture of the heart muscle during placement of the pacemaker leads. This usually requires emergency management.
It is uncommon for any of these complications to be life-threatening.
Precautions to Take
If you have had a pacemaker inserted, it is essential take certain precautions to prevent damage to the pacemaker. Some of the commonly advised to precautions include –
1. Inform security at airports that you have a pacemaker
Sometimes,when going through security checks at the airport, it is possible that the pacemaker triggers the alarm system.
In order to avoid any confusion and apprehension, always carry some form of an identification card that describes the type of device you have implanted under the skin.
This would have been provided to you when being discharged from hospital after pacemaker implantation. When the security personnel are using a handheld metal detector as a part of their search, request them not to hover the device over your pacemaker for too long.
2. Avoid placing cellphones nearby
If you are of the habit of placing your cellphone in your shirt pocket, make sure you do not do so after you had a pacemaker implanted.
While it is uncommon for cellphones to interfere with pacemaker signals, it is possible for it to happen and the circumstance is best avoided completely.
Cellphone signals can sometimes interfere with how the pacemaker works and may withhold the generation of electrical signals within the pacemaker. This can in turn reduce the heart rate and may lead to the development of symptoms.
Prevent any problems by keeping your cell phone at least 6 inches away from your pacemaker.
3. Inform any doctor you see that you have a pacemaker
Sometimes, doctors may arrange certain investigations such as an MRI scan or shock treatment which can interfere with the function of pacemakers. These days, MRI safe pacemakers are available but are not implanted for most patients due to the higher cost.
4. Avoid working near high-voltage equipment
High-voltage equipment such as transformers and generators can sometimes affect the functioning of your pacemaker. It is recommended that you stand at least 2 to 3 feet away from these.
5. Avoid keeping headphones close by
The headphones used for MP3 players contain a magnetic material within them that can interfere with the functioning of pacemakers. It is recommended that they be placed at least 3 cm away the device. Wearing headphones to listen to music will not affect the pacemaker.
6. Avoid contact sports
A short while after pacemaker implantation, patients can restart their normal exercise and physical activity. However, it is recommended they refrain from participating in contact sports as a direct hit to the chest can dislodge the pacemaker.
**Note: Devices such as the television, microwave oven, electric shavers, drills and radios do not interfere with pacemaker function
Frequently Asked Questions
What about the future?
Once your pacemaker has been implanted, you are likely to require annual checks to ensure that it is working correctly and that the battery life is good. As the battery approaches its end of life, the hospital personnel will recommend a change of the pulse generator. The leads do not need to be changed. There are rare cases when both the pulse generator and the leads need to be changed.
Below are some questions that patients ask us after they have pacemakers implanted.
How long does the battery last?
The battery life of most pacemakers ranges between 5 to 10 years. This is constantly monitored by a hospital personnel.
Can I participate in sports and similar activities?
If you are an active individual who participate in sporting activities, you may be reassured to know that pacemakers do not interfere with your daily activities. If you wish to participate in athletic activities or aerobic activity such as running, swimming and cycling (after getting the all clear from your doctor), then you can do so.
What about sexual activity?
Once the pacemaker wound has healed and the initial checks have confirmed the pacemaker to be working properly, there should be no problem re-commencing normal sexual activity.
What happens after death?
If an individual with a pacemaker is terminally ill or has died, the cells within the heart muscle can no longer conduct the electricity that is generated by the pacemaker. Consequently, a working pacemaker will not generate heart contractions. In such a situation, the it will be switched off or deactivated. Contrary to popular belief, pacemakers do not prolong life if a patient is terminally ill.
There may be rare cases when patients are so ill that having a working pacemaker may be prolonging their suffering. Doctors may discuss turning off the the device with family members and the patient if such a situation arises.
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