The body contains a natural pacemaker, but if this is not working effectively, an artificial pacemaker can be installed to help monitor this condition more effectively. Pacemakers can be implanted to help to control the heartbeat. They may be inserted after an overdose, surgery or heart attack as a temporary measure to keep the heartbeat steady, but permanent pacemakers may be inserted to manage a slow heartbeat or bradycardia. In some cases pacemakers are also used to treat heart failure. How does the implanted pacemaker of the heart work? Are there any risks of implanting it?
Natural Pacemaker of the Heart--How the Heart Beats
The sinus node acts as a natural pacemaker for the cardiac conduction system that is responsible for the heart rate. This system creates an electrical impulse that is sent through the heart muscle, causing it to contract, which then pumps blood as necessary. The sinus node itself is a cluster of cells in the upper right chamber of the heart where these electrical impulses are generated. The signal travels from cell to cell until they reach the atrioventricular node (AV node) which is found in the center of the heart. This node slows down the electrical current before it reaches the ventricles to make sure that the atria can contract before the ventricles are stimulated. Finally the electrical impulse will reach the lower part of the heart.
Implanted Pacemaker of the Heart
An artificial pacemaker is a device that is around the size of a 50 cent piece that is surgically placed near the heart to help control the heartbeat. Those with heart arrhythmia or other conditions that cause an abnormal heartbeat will require this device. The aging process can also disrupt the heart rate, making it beat more slowly than it should. Damage from conditions such as a heart attack can also cause the heart to beat abnormally. Inserting a pacemaker only requires minor surgery, but patients may need to take care to monitor their condition after it is inserted.
What a Pacemaker Does
A pacemaker is an electronic device that is designed to mimic your natural pacemaker. There are two parts to a pacemaker, the pulse generator and the leads or electrodes. The pulse generator is a small container holding a battery and circuitry that is used to send electrical pulses to the heart. Leads are one to three flexible electrodes that are places in each chamber of the heart to deliver these pulses as necessary. The pacemaker will detect if the heart is beating too slowly and send a signal to increase the heart rate. Pacemakers may also contain sensors that will detect breathing rate or motion to increase heart rate to match when the body may need more oxygen.
Types of Pacemakers
There are three basic types of pacemakers. A single-chamber pacemaker will carry an electrical impulse to the right ventricle of the heart. Dual-chamber pacemakers carry pulses to the right ventricle and the right atrium to help control reactions between these two areas. Biventricular pacemakers are designed for those who are suffering from heart failure. In this case, both lower chambers of the heart will be stimulated to ensure that the heart beats efficiently and to help ensure that the ventricles pump together like they should.
Risks of Implanting Pacemaker
Risks associated with inserting a pacemaker are similar to those from other types of surgery. These include infection around the surgical site, swelling, bleeding or bruising around the generator site, collapsed lung, damage to the nerves and blood vessels near the device, puncturing the heart muscles leading to bleeding into the lining of the heart or allergic reaction to dyes or anesthesia used during the procedure. These occurrences are not common, but your doctor should outline any potential risks you face before the procedure begins.
What Can You Expect Before and After the Surgery
The surgery will often be performed while you are awake, though you will be provided a sedative and the area around the surgical site will be numbed. Flexible electrodes will be inserted through the major vein under the collarbone and the doctor will use an X-ray to guide them to the proper location in the heart. The other end of these electrodes will be attached to a pulse generator which is placed under the collarbone.
After the procedure you may need to stay in the hospital overnight to ensure that the pacemaker is programmed correctly. After this the pacemaker will be able to be checked remotely. Any scheduled visits with your doctor can be made based on alerts from the pacemaker regarding blood flow, rhythm and battery life. You should avoid strenuous activity for around a month after surgery to be safe. You may also need to take over the counter pain medication to relieve any discomfort from the surgery.
What Precautions Should You Take?
- You may talk on a cell phone, but you should not place a cell phone that is turned on near your pacemaker as the pacemaker may mistake the phone signal for your heartbeat and alter its settings.
- Tell your doctor you have a pacemaker before any procedures that use magnetic resonance imaging, radiation, electromagnetic energy or items like shock waves that are used to break up gall or kidney stones.
- Surgeries that use electrocautery may also interfere with your pacemaker. Passing through a metal detector should not harm your pacemaker, but it could set off the metal detection alarm. If security personnel then ask to use a metal detector ask them to avoid holding it near the pacemaker for any longer than necessary or submit to a different type of search to avoid any potential interference.
- You should avoid standing within 2 feet from high voltage equipment, welding equipment or motor-generators. If you work with such machinery, your doctor can investigate to determine if your workplace is safe.
Once the pacemaker has been installed a battery can last for 5-10 years. When it wears out the pulse generator will be replaced. Any portion of the pacemaker that wears out over time can be surgically replaced. Pacemakers may cause fainting, lightheadedness or fatigue if they slow the heartbeat too far, but most modern pacemakers adjust to match current levels of activity, reducing this risk.
Watch a Video: The following video provides additional insight regarding how pacemakers work with the natural mechanics of the heart