Pacemaker

A pacemaker is a small device implanted in the chest to help control your heartbeat. It's used when the heart beats too quickly, too slowly or irregularly due to a heart attack, heart failure or another problem that has damaged the heart's natural electrical system. A pacemaker mimics that system by sending out painless electrical signals that stimulate heart muscle contraction – the first part of the heart's pumping action. Having a pacemaker can relieve the dizziness, fainting episodes and shortness of breath caused by a slow or unsteady heartbeat.

A pacemaker is battery powered. Most consist of two parts: the pulse generator, a small metal container about the size of a matchbox that contains the battery and electronics, and the leads, thin wires that conduct the electrical signals. Most pacemakers are placed under the skin of the chest and connected to the heart through the leads. But there are also leadless pacemakers, which are placed directly in the heart through a minimally invasive procedure.

Pacemakers are usually implanted as a permanent treatment. But they're sometimes used as a temporary measure to stabilize heart rhythms in people recovering from a heart attack, heart surgery or a medication overdose that slowed their heart rate.

Types of Pacemakers

There are many types of pacemakers, designed to treat a range of heart conditions. We use the full array at UCSF, and our heart team has expertise in implanting every kind. Here's help with understanding the types:

A single-chamber pacemaker has a single lead that connects to the heart's lower right chamber (ventricle) or upper right chamber (atrium).
A dual-chamber pacemaker has two leads that connect to both the upper and lower chambers on the heart's right side. This device helps control the timing of contractions between the chambers.
A biventricular pacemaker has three leads, which connect to both chambers on the heart's right side plus the lower left ventricle. This type is used to regulate the heart's beating in some patients with advanced heart failure.
A pacemaker may be combined with an implantable cardioverter-defibrillator (ICD), which can shock your heart back to a normal rhythm if it becomes dangerously fast. This device is used to prevent sudden death.
A leadless pacemaker is implanted inside the heart through a minimally invasive procedure.

Your doctor will recommend the best type for you based on your symptoms and specific heart condition.

Evaluation

To determine whether a pacemaker is appropriate for your condition, you'll be checked for certain problems that may have damaged your heart's electrical system. These include:

Age-related changes in the heart
Coronary artery disease
Heart attack
Heart block (also called atrioventricular or AV block), a problem in the heart's electrical system that causes a slow heart rate

As part of your evaluation, you may have the following tests:

Electrocardiogram (EKG) – a painless test that records the electrical activity of your heart and detects abnormal rhythms
Echocardiogram – uses sound waves to create images of your heart, which can show blocked blood flow
Stress test – a type of EKG that monitors your heart's ability to function during exercise
Holter monitor – a portable EKG that you wear for 24 to 48 hours while it records your heart's activity
Zio patch – a portable heart monitor that records your heart's rhythms for two weeks

Based on your test results and symptoms, your doctor will determine whether a pacemaker is right for you and, if so, which type. For instance, if the tests show you have a weak heart that doesn't contract in a coordinated way, you may be a candidate for a biventricular pacemaker.

Procedure

The procedure to place a pacemaker depends on the type.

Pacemaker with leads – This requires a one- to three-hour surgery and general anesthesia. The surgeon makes a small incision just below your collarbone through which the lead is inserted into a nearby vein. Guided by X-ray images, the surgeon threads the lead to your heart and secures it in place with a tiny screw; the other end attaches to the pacemaker. Your doctor will then program the pulse generator and place it under the skin of your chest, near the collarbone. You may see a bump under the skin where the device is located.

Leadless pacemaker – This is implanted in a minimally invasive procedure, using a thin, flexible tube called a catheter to access the heart. After an injection to numb the area, a catheter containing the pacemaker is inserted into a blood vessel in your groin. The doctor threads the catheter through this vessel to the lower right chamber of your heart, then releases the pacemaker and attaches it to heart tissue. The catheter is then removed.

Recovery

After your procedure is finished, you'll be monitored in a post-op area for a brief period. Most patients spend the night in the hospital, but sometimes the procedure can be done safely on an outpatient basis, meaning you can go home the same day. Before discharge, your doctor will make sure the pacemaker is programmed properly for your needs.

Over the next month, you should avoid rigorous exercise and lifting anything heavier than 10 pounds. If you experience discomfort, you may need to take over-the-counter medications. Ask your doctors which pain relievers are safe for you.

You will be scheduled for a one-week checkup to make sure your incision looks OK. This may be in person or via video. About one month after the procedure, you will return for a follow-up visit with your doctor.

You will be monitored by our device clinic or your local doctor. We'll provide you with special equipment that allows you to hook up your pacemaker to a phone line for remote testing that looks at whether everything is functioning properly and detects any abnormal heart rhythms. The pacemaker can be reprogrammed as needed.

Risks

In general, the risks associated with a pacemaker are from the surgery to place it. Most are temporary, and life-threatening complications are rare. Risks include:

allergic reaction to anesthesia
bleeding
bruising
damaged nerves or blood vessels
an infection at the incision site
collapsed lung (very rare)
punctured heart (very rare)

Electrical interference

Modern pacemakers are less sensitive to other electrical devices than older models, but certain appliances or machinery can still cause interference. For example, you should avoid: