A pacemaker is a small electronic device which is implanted in people for a slow heart rhythm (bradycardia). For a complete description of the different types of slow heart rhythms, please see the bradyarrhythmias section. Once implanted, the pacemaker is able to pace the heart to prevent a slow heart rhythm.
Typically, a person receives a pacemaker because they have been shown to have a slow heart rhythm and are experiencing symptoms from that slow rhythm. Symptoms that can be experienced range from fatigue and inability to walk even short distances without becoming short of breath to dizziness and even passing out (syncope).
The pacemaker is basically composed of 4 components: the outer metal case, the battery, the circuit board, and the lead(s). The lead (or leads, depending on the type of pacemaker) are insulated wires that travel through the veins into the heart and are connected to the pacemaker. [Click here to see a picture of a pacemaker lead]. The battery and circuit board are sealed within the metal casing of the pacemaker. The battery provides the energy to run the circuit board and pace the heart and the circuit board controls the timing and multiple functions of the pacemaker.
The number of leads (one or two) implanted with the pacemaker will depend on each individual case. Your physician will decide which type of pacemaker is best for your clinical situation. Many pacemakers are implanted with two leads – one in the upper chamber of the heart (atrium) and one in the lower chamber (ventricle) although in certain patients, a pacemaker with only one lead is required. Pacemakers with two leads are called dual-chamber pacemakers while those with one lead are called single-chamber pacemakers. There are some recently approved pacemakers in use for patients with heart failure that have three leads - one in each ventricle (right and left) and one in the right atrium (these are called biventricular pacemakers). Patients need to meet specific criteria to be eligible for a biventricular pacemaker.
The pacemaker can observe the native heart rhythm (sense) or it can deliver small electrical impulses through the lead(s) to the heart muscle to cause it to contract (pace). The native heart rhythm and the settings of the pacemaker will determine how often the pacemaker actually needs to pace the heart muscle. The physician can change the settings of the pacemaker via a pacemaker programmer which is a modified computer with a wand that enables non-invasive communication with the pacemaker. Most pacemakers have a rate response function built-in which can be activated by the physician. This function enables the pacemaker to increase the patient's heart rate if it senses that the patient is engaged in physical activity (i.e. walking, running, etc...). There are multiple other programmable options which can be changed by the physician to optimize the function of the pacemaker. The most recent pacemakers can help in collecting heart rhythm information (i.e. on fast arrhythmias from the upper and lower chambers of the heart) and making it available for the physician to review.
Before the Procedure:
You will be told not to eat or drink anything after midnight on the night before the procedure. Follow your physicians’ instructions for taking medications the day of the pacemaker implant. You will also be required to have certain blood tests drawn at least a few days prior to the procedure. If you are of childbearing age a pregnancy test will also be performed to ensure that you are not pregnant.
After arriving at the electrophysiology laboratory, one of the nurses will assist you in changing into a hospital gown and will place an intravenous to assist us in administering sedation and medications during the procedure. Electrocardiogram electrodes and pads will be placed on your chest and back to monitor your heart rhythm throughout the study. You will be placed onto the procedure table lying flat on your back. You will notice a large camera and video monitors nearby. The x-ray camera will be used to view the location of the pacemaker leads (insulated wires) that will be placed in your heart. The area around the pacemaker implant site (usually the left upper chest) will be cleaned carefully by the nurse. Your body will be covered with sterile sheets to prevent any infection during the procedure. The nurse will also administer some sedation through the intravenous to make you comfortable throughout the procedure. Click here to see images of the electrophysiology laboratory and staff at Lenox Hill Hospital.
The physician will inject a small amount of anesthetic into the skin in the upper chest area where the pacemaker will be placed. You might feel a pinch and some burning during this part of the case but otherwise you shouldn’t feel any other discomfort during the procedure. A small vein in the chest area is located which is used to introduce the lead(s) into the right side of the heart. If this vein is too small for use or not located, a vein underneath the collar bone is used. The physician moves the lead(s) into the heart using x-ray guidance (fluoroscopy). The leads are tested to be sure they are in a stable position and are then secured to the tissue. The leads are then attached to the pacemaker and the pacemaker is placed underneath the skin. The wound is then closed by the physician and a dressing placed to maintain a clean area.
The entire procedure can last anywhere from 1½ to 2½ hours depending on each particular case. You will be kept comfortable throughout the procedure. The staff will constantly be monitoring your vital signs throughout the procedure. If you feel any discomfort at any point during the procedure you should tell the staff immediately. Most patients recall little if any of the procedure and are usually very comfortable throughout.
You will be asked to lie in bed for 2 to 3 hours after the procedure is finished to allow the sedation to wear off. A bedside chest x-ray might be required. After this time you can get out of bed and walk around if you feel up to it. You will need to monitored in the hospital at least overnight if not for 2 days after the procedure.
You shouldn’t perform any heavy lifting or heavy physical exertion (including sexual intercourse, jogging, weight lifting) for at least 2-3 weeks after the pacemaker implant. Your physician can recommend which specific forms of exercise you will be allowed to perform. A small bruise (black and blue mark) or small lump can sometimes appear over the pacemaker implant site, which typically resolves over 2-3 weeks. A large lump or worsening pain at the pacemaker implant site, swelling in the arm or fever should be reported to your doctor at once.
As with any invasive procedure, there are some risks involved in having a pacemaker implanted. A small amount of bleeding into the pacemaker pocket or a localized infection of the pacemaker wound is possible. There is about a 1% risk of nicking the lung and causing it to partially or fully collapse. Very serious side effects such as damage to the heart muscle wall or blood vessels, blood clots, stroke, and heart attack are rare. Death is very rare. The vast majority of patients undergoing a pacemaker implant do very well and do not experience any complications. You should speak with your physician regarding these risks and understand them prior to undergoing the implant.