A cardiac pacemaker is a small device that is surgically implanted in the chest to monitor the heart and control heart rate in the presence of arrhythmias. It can speed up your heart rate, for example, if your pulse starts to decrease so that your heart rate stays within normal limits (between 60 to 100 beats per minute at rest).
With a pacemaker, it is possible to prevent problems in the heart that affect blood getting to the rest of the problem. Symptoms of a pumping problem include excessive fatigue and shortness of breath. A pumping problem can be a life-threatening situation.
A pacemaker can be temporary, and can be placed to treat a cardiac abnormality. It can also be permanent, and may be implanted to treat chronic problems like sinus node dysfunction.
How it works
A pacemaker continuously monitors the heart and identifies abnormal heart rates (like slow rates) or skipped beats. This device is stimulated when a cardiac abnormality occurs, and sends an electrical signal to the heart to reset its heart beats.
A pacemaker contains two parts: the generator (which contains the battery and the electronic circuitry to manage heart beats), and the electrodes (also known as the leads, which are the wires that connect the heart to the generator and conduct the electric impulses).
There are different types of pacemakers that can be used for the management of specific cardiac diseases. Dual-chamber pacemakers and bi-ventricular pacemakers, for example, are used for the treatment of severe congestive heart failure. These pacemakers consist of 3 parts: the generator, the electrodes and the programmer, which is a type of external computer that is used to adjust the pacemaker settings.
Pacemakers are powered by batteries that last on average for 5 to 15 years. However, there are some cases in which the batteries last for even less time. When batteries are close to running out of energy, they are swapped for fresh ones with a simple surgical procedure.
Types of pacemakers
The main types of pacemakers include:
- Permanent pacemaker: This pacemaker is implanted in the chest for long-term use. The electrodes are attached to the atria and ventricles of the heart through surgery.
- Transcutaneous pacemaker: This pacemaker consists of 2 electrodes that are placed over the skin, one on the chest and another on the back. They are connected to a defibrillator, which generates electrical charges to stimulate the heart to start beating again. These are used in medical emergencies, like bradycardias or AV blocks.
- Transvenous pacemaker: This pacemaker consist of a wire-electrode that is placed into the right ventricle through a cut in the jugular or subclavian artery. It is also used in medical emergencies, like the treatment of serious bradycardias.
Pacemakers that are used just for emergency situations are used temporarily, and removed once the imminent danger has resolved.
What is it used for
A pacemaker is recommended by a cardiologist when the patient has an illness that causes severe bradycardia, which is a decrease in heart rate of less than 40 beats per minute. Examples include:
- Sinus node dysfunction
- AV block
- Bundle branch block
- Neurocardiogenic syncope
- Carotid sinus hypersensitivity
- Hypertrophic cardiomyopathy
- Serious congestive heart failure
- Congenital heart disease
In addition, a pacemarker can also be recommended by a cardiogist following a heart attack, a heart transplant, to detect and manage tachycardio or treat a cardiac abnormality caused by medication or drug abuse.
How to prepare for pacemaker surgery
There are some considerations to keep in mind to prepare for pacemaker surgery, like asking your cardiologist any questions you may have about the surgery and recovery, and being aware of how medication, vitamins and nutritional supplements that you already take may be affected. You should report any of these to your surgeon, as they can affect recovery, anesthesia, the risk of blood clots and the risk of hemorrhage. You should also report any allergies and other medical issues you may have.
In addition, you should also avoid smoking or drinking alcohol prior to surgery. Be sure to bathe with soap that is recommended by your doctor, and to avoid the use of moisturizers, lotions, perfume and deodorant. All jewelry and contact lenses should also be removed prior to surgery.
Patients should fast for at least 4 hours prior to the scheduled surgery time. Any necessary medications should only be taken with sips of water.
How pacemaker surgery is done
Pacemaker surgery consists of the implantation of the device by a cardiac surgeron. It is a simple and quick procedure that generally only takes an hour or two.
Before surgery is started, IV access is established by the nurse to hydrate the patient and administer medications. It is also used to administer general anesthesia or light sedation.
Next, a small cut near the shoulder is done to reach the subclavian vein. It is here where a thin wire is inserted and fed to the heart until it reaches the right ventricle. Once it reaches the right ventricle, an electrode is placed. The other end of the wire is connected to the pulse generator, which is inserted beneath the skin, close the clavicle, by the shoulder.
During surgery, the doctor will monitor the insertion and position of the pacemaker through X-rays, to ensure that it is properly inserted and placed in the right spot.
Surgery after-care
Because this is a simple procedure, patients are often discharged home the next day. However, it is important for post-op patients to rest for the first month after surgery and to attend all follow-ups with the cardiologist to monitor their general health status.
In addition, other necessary after-care considerations while recovering include:
- Keep a pacemaker information card in your wallet, which outlines all your pacemaker settings. You should also keep a list of your emergency contacts with this card.
- Take your medications at the right times, as prescribed by your doctor.
- Evitar movimentos bruscos envolvendo o braço do lado em foi colocado o marcapasso;
- Avoid intense exercise, driving or physical activity like jumping, carrying babies, lifting or pushing heavy objects.
- Avoid using your cellphone on the same side the pacemaker was inserted. You should also avoid placing your cellphone in your shirt pocket or pant pockets.
- Avoid placing electronic devices within 15 cm of proximity to your pacemaker. Examples include music players, remote controls, televisions, drills, and electric razors.
- Inform any high-security officers, like at the airport or bank, about your pacemaker to avoid walking through any X-rays. While X-rays will not interfere with pacemaker function, metal will likely be detected on the body, which can warrant a thorough search.
- Stay at least 2 meters away from a microwave, welding equipment, or generators.
- Avoid electrical shocks and direct trauma to the pacemaker
- Avoid any medical exams or procedures like MRI, ablation, radiation therapy, or laser hair removal, as these can interfere with pacemaker functioning.
In addition, the use of some equipment is contraindicated for patients with pacemakers, like an electric scalper and a defibrillator. You should inform your family, friends and health care professionals about your pacemaker so that your pacemaker is turned off before any kind of procedure that may cause interference.
People with pacemakers can lead a normal life - they only need to avoid strenuous activity for the first 3 months after placement. Before starting to work out or attending physiotherapy, you should see your doctor to ensure your safety.
Pacemaker follow-up
After implantation, it is important to attend regular follow-ups with your cardiologist for assessment of your pacemaker. This will ensure your pacemaker continues to be safe and adequately functioning These appointments will often look at the following factors:
- Parameters that your pacemaker is set at to initiate pulses (e.g. electrical impulse for heart beats under 40 beats per minute)
- Battery status
- Stimulation and sensing thresholds
- Any blocks along the electrode wires
Ensuring that your pacemaker is functioning properly is also important for extending the battery life of your pacemaker. The less it is used, the longer it will last. Doctors will also use these follow-up appointments as opportunities for health education.
A follow-up is recommended at least one month after insertion, and then every 6 to 12 months with normal pacemaker functioning.
Possible complications
The main complications associated with pacemaker surgery are infection in the wound site, bleeding or bruising in the insertion area.
You should seek medical attention or proceed to the emergency room if your have a fever over 37.5ºC (or 99.5ºF), if you notice a blue color in your skin or nails, or if you experience shortness of breath or chest pain.
