First let us discuss some of the basic facts about your heart and how it works. Your heart is a pump made of special muscle tissue. It pumps blood throughout the body sending oxygen and nourishment to all the cells and organs in your body. In order to beat regularly, your heart responds to electrical impulses produced by a special centre called a natural pacemaker. Everybody has a natural pacemaker (Sino-Atrial Node).
Your natural pacemaker (S-A node) is located in the upper right portion of your heart. From this centre, the impulses (i.e. electrical activity) travel down special electrical pathways in your heart, causing your heart to contract rhythmically and pump blood. Your natural pacemaker regulates how fast your heart must beat in order to ensure proper amount of blood and oxygen to flow through your body. An average heart rate at real is between 60 & 80 beats per minute in an adult, but heart rates can vary for a number of reasons.
Most pacemakers are recommended when a patient experiences symptoms that are due to an inappropriately slow heart rate.
There are many causes of a slow heart rate. Most of these commonly involve the heart's own pacemaker, the S-A node or the hearts own electrical conduction system (wiring systems). These diseases can cause your heart to:
When any of these things happen, your heart does not pump enough blood to meet your body's need. As a result you may feel tired, weak, sluggish, dizzy, lightheaded or short of breath. In certain cases, the problem is severe enough to cause the patient to "faint". Medical science has an answer to your problem - it is to place a new pacemaker in your body.
A pacemaker is actually a two-part system. To implant the pacemaker, only a minor operation using local anaesthetic is required.
The two parts of the pacemaker are:
The pulse generator controls the pacing system. It contains the battery and electronic circuitry which produce the electrical impulses as needed and acts as a brain within the system. A typical pulse generator is very small in size, often less than two inches wide and a quarter inch thick, most weigh about an ounce or less. The pacing lead is the wire which goes from the generator to the inside of the heart carrying the electrical signal. The whole system is extremely reliable and dependable and works in a manner similar to your natural pacemaker.
Most pacemakers are single chamber , i.e. they stimulate only one chamber of the heart. They need one pacing lead which not only can deliver a small electrical impulse to the heart muscle, but can also sense when the heart is beating properly on its own and signal the pacemaker to hold off on the next electrical impulse (demand pacing).
Many pacemakers, inserted in recent years, are dual chamber pacemakers , i.e. one electrode is implanted in the right atrium (upper chamber of the heart) and the other in the right ventricle (lower chamber of the heart). An impulse goes first to the atrium and then a split second later, the other impulse goes to the right ventricle. This more nearly approximates the action of the normal heart and allows for a greater exercise tolerance, due to the coordinated, sequential pumping of the upper and lower chambers.
Some pacemakers offer a variety of functions that you may or may not need. These functions include:Telemetry
It is a "two-way" conversation between your pacemaker and a computerised programmers. This two-way conversation allows your doctors to more accurately evaluate and adjust your pacemaker according to your needs. This is simply done by computer assessment from outside your body even though the "generator" is implanted inside your body.Programmability
It allows your doctor the opportunity to reprogram the electrical settings of your pacemaker as needed to improve your quality of life.Rate Modulated Pacemaker
Some pacemakers can recognize when your body needs an increased heart rate. These devices are called rate modulated pacemakers and have the ability not only to sense your heart's own production of electrical impulses, but they also use one or more sensors to monitor your body's need for an increased heart rate.
Your doctor will choose a pacemaker which is best suited to your needs and will discuss it with you.Pacemaker Implantation
Implanting a pacemaker is now a very common procedure which, most often, is done in an operating room or in a Cardiac Catheterization Laboratory. Generally, it takes about an hour.
The procedure normally requires only minimal anaesthetic which means you will be relaxed but awake. However, you will have a local injection of anaesthetic to lessen any discomfort at the minor operation site (incision site).What Happens Before the Surgery?
As with many surgeries, you will be asked not to eat or drink for several hours before surgery. Preparation often begins with washing your upper chest area, using antibacterial soap to protect the incision from infections. Any hair on the upper chest and shoulder will be shaved. You will have an IV line placed in a vein in your arm. This is used to give you medication, if required.What Happens During the Surgery?
You will be taken to a special room full of equipment and people. You will lie on a bed with your arms safely secured at your sides with padding placed at your elbow. It is important that you do not reach up or move your arms during the procedure.
ECG electrodes will be placed on your chest, back, arms or legs, so that your heartbeat can be monitored during the procedure.
Your chest will be washed again and then covered with special drapes and sheets. A local anaesthetic, similar to that which a dentist uses to numb your gums and teeth, will be injected to numb the incision area.
A small incision is made under the right or left collar bone as considered appropriate by your doctor. A needle is introduced into a vein lying near the surface of the chest close to the collar bone.
Then the pacemaker lead is inserted through the needle into the vein and is advanced to the heart under X-ray imaging. When in the heart, the lead is secured in the right position. Next, a space is created under the skin on the front of the chest and the pulse generator is slipped into this pocket. After the pacemaker has been tested to make sure it is working properly, the skin pocket is sewn up, completing the procedure.
When the pacemaker and the leads are being inserted, you may feel some pressure. If you begin to feel any discomfort, let the doctor know immediately so you can receive some additional medication to keep the area numb. You may be asked to take deep breaths and to cough vigorously, while your doctor watches an X-ray of your heart on X-ray video. This is done to ensure secure placement of the leads.What Happens After the Surgery?
You will probably spend a short time in a recovery room and then will be shifted back to your hospital room. You may have a little soreness around the incision line, where the pacemaker was implanted. This is often treated with pain medication, if needed. You can usually go home, anywhere within a day or two after surgery - it all depends on your particular case.What About the Recovery Period?
You will probably be aware of the pacemaker for a while. This is a normal feeling and generally will lessen with time. Sometimes, there will be a black and blue mark in the area of the pacemaker. This is from the surgical procedure and will go away with time. If however your incision becomes red, warm, more painful, swollen or starts to drain fluid, notify your doctor immediately. Also call your doctor promptly if you develop a fever. Do not wait for your next scheduled visit.
During the first few days after surgery, avoid sudden, jerky movement with your arms or stretching or reaching over your head. Your doctor will tell you when to resume your usual bathing routine and other normal activities. The symptoms you experienced from the original abnormal heart rhythm should diminish and, hopefully disappear altogether. If you notice new sensation as your body adjusts to your pacemaker, tell your doctor. This will help the doctor adjust the electrical settings of your pacemaker to better suit your particular needs.What About Follow-Up Care?
Pacemakers are extremely dependable devices. However, it is important to periodically check the pacemaker to make sure that it is functioning properly and that its settings remain appropriate for your medical needs.
When your pacemaker is implanted, it is adjusted or programmed to fit your needs. These needs may change over time and when they do, it is a simple process to re-program your pacemaker during a visit to the Cardiology Clinic or Cardiology Department.
A typical follow-up will usually include a brief physical examination, an electrocardiogram, and a detailed evaluation of how well your pacemaker is performing. Examining and adjusting your pacemaker is quick and painless. Your doctor has special equipment (computerised programmer) that communicates with the pacemaker, allowing adjustment of its function without any additional surgery.How Long Should a Pacemaker Last?
Advances in technology have made pacemakers safe, reliable and long-lasting. Modem batteries lose power slowly, not all at once, accordingly, there is no danger of unexpected failure. However, periodic checks of battery function are important.
Pacemaker longevity depends upon how hard the battery inside the pulse generator has to work, based upon how much energy is required to pace your heart and how the system is programmed for your need. In general, pacemaker batteries last anywhere from 10-15 years, but could last longer or shorter depending on any one specific circumstance.
Pacemaker batteries usually do not stop suddenly. One of the purposes of your follow-up care is to monitor battery status. Your pacemaker will give ample warning (months ahead of time) that the batteries are reaching depletion. At this time your doctor will schedule replacement procedure. The same minor surgery is required to replace the pulse generator as performed during the original implantation. Normally, this is easier than the original procedure because the leads are already implanted and usually do not require replacement. They are simply reconnected to the new pulse generator.
Do not wait for the severity of the symptoms to increase.
You may comfortably use common household appliances such as
Special precautions should be taken if a pacemaker patient is considered for the following procedures:
X-Ray and thermal treatment does not effect a pacemaker.