Pacemakers

In contrast to ICDs, which are used to control tachycardias, pacemakers are used to control bradycardias.

What is a Pacemaker?

The pacemaker is essentially a small, lightweight, electronic device that delivers electrical impulse to the heart at a set rate. This electrical impulse enables the heart to beat.

A pacing system consists of two parts: a pacemaker, and a pacing lead.

The pacing lead is an insulated wire that carries the tiny electrical pulse from the pacemaker to the heart muscle. It can also relay information about the heart's activity back to the pacemaker.

Who Needs a Pacemaker?

When the normal electrical system in the heart is diseased, the heart may beat too slowly. This can lead to symptoms of weakness, fatigue, lightheadedness, dizziness, or fainting (syncope). In such cases, a pacemaker can be used to substitute for the natural pacemaker and make the heart to beat at an appropriate rate.

The two most common conditions that require treatment with a pacemaker are Sick Sinus Syndrome (where the SA node is inappropriately slow due to disease), and Heart Block (where there is a delay or stoppage of electrical transmission through the AV Node, the electrical "junction box" between the atria and the ventricles, due to disease in the wiring).

What are the Different Types of Pacemakers?

Pacemakers come in different shapes and sizes. They are all relatively small and lightweight (approximate weight 1-13/4 ounces or 22-50 grams.)

Depending upon the patient's heart condition, the physician will prescribe a single or dual chamber pacemaker.

A single-chamber pacemaker paces either the right atrium or, more commonly, the right ventricle with one electrode.

A dual-chamber pacemaker paces both the right atrium and right ventricle of the heart. This requires two pacing leads. A dual-chamber pacemaker is the most common type of pacemaker implanted today.

A rate-responsive pacemaker varies the heart rate depending upon the person's level of activity, respiration, or other factors, thereby simulating the natural pacemaker. Rate-responsive pacing can be part of single-chamber and dual-chamber pacing. Most pacemakers implanted today are rate-responsive.

How is the Pacemaker Implanted?

Pacemaker surgery is often done using a local anesthetic in an operating room under light sedation. The person usually returns home the next day. Occasionally, a patient who requires other surgery, such as a coronary bypass, will have the pacemaker implanted at the same time as the other surgery.

What Should You Expect During this Procedure?

Before the procedure:

• The doctor will explain the procedure, including its potential benefits and risks, to you. This is a good time to ask any questions or share any concerns that you may have. You will then be asked to sign a consent form.

• The night before surgery, your doctor will give specific instructions. Some of these instructions may include:
  

  • Avoid eating any food or drinking any fluids after midnight.

  • Advice on taking your medication. You may need to alter your medications, depending upon your condition.

• Tests, including EKG, blood tests will be done a day or two prior to the procedure.

• A small IV will be inserted in a vein in your arm.

• Be sure to mention to the doctor (or nurse) if you have experienced any allergic reactions to any medications, or if you may be pregnant.

• Pacemakers can be inserted near the right or left shoulder. If you pref

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