Pacemaker for bradycardia

Treatment Overview

A pacemaker is a battery-powered device about the size of a pocket watch that sends weak electrical impulses to “set a pace” so that the heart is able to maintain a regular heartbeat. There are two basic types of pacemakers:

• Single-chamber pacemakers stimulate one chamber of the heart, either an upper chamber (atrium) or, more commonly, a lower one (ventricle).
• Dual-chamber pacemakers send electrical impulses to both the atrium and the ventricle and pace both chambers. A dual-chamber pacemaker synchronizes the rhythm of the atrium and ventricles in a pattern that closely resembles the natural heartbeat.
• Biventricular pacemakers pace the rhythm of the heart's lower chambers (ventricles) so that the chambers contract at the same time. Biventricular pacemakers are used in people who have heart failure and problems with the heart's electrical system. Biventricular pacemakers are also called cardiac resynchronization therapy (CRT).

Most new pacemakers are rate-responsive, or physiologic, pacemakers. This type of pacemaker varies its rate to cause the heart to beat faster when you are exercising to meet your body's increased needs or slower when you are at rest. Another type, the fixed-rate pacemaker, sends electrical impulses at a set rate that does not vary either faster or slower. Both types of pacemakers kick in when the heart rate drops to a predetermined "slow" level.

Permanent pacemakers are surgically implanted into the chest. The procedure to implant a pacemaker is considered minor surgery. It can usually be done using local anesthesia. The procedure takes about an hour. Permanent pacemakers are powered by batteries. The batteries usually last 5 to 15 years before they need to be replaced.

Temporary pacemakers are located outside the body and attached to the heart by a wire threaded through a neck vein or leg vein or through the chest wall. Temporary pacemakers are most commonly used for a short time following heart surgery or in emergency situations.

What To Expect After Treatment

Most people can go home 1 or 2 days after having a pacemaker implanted and can return to normal activities within 2 weeks. You should avoid driving or participating in vigorous physical activity that involves the upper body for several weeks after having a pacemaker implanted.

Why It Is Done

Historically, pacemakers have been used to treat slow heart rates by sensing when the heart rate falls below a certain rate and then pacing the heart to increase it to a set rate. But newer rate-responsive pacemakers can alter the heart rate to a faster or slower rate based on your activity.

How Well It Works

Pacemakers stimulate the heart to speed up when it beats too slowly. They can also substitute for the natural pacemaker of the heart (SA node) or the heart tissue that regulates the beating of the ventricles (AV node).

Risks

Pacemakers allow people to return to normal, active lives. Most people have very few limitations, if any. But some activities and situations can interrupt the signals sent by the pacemaker to the heart. You may need to modify some of your activities. Follow your doctor's specific instructions about care and precautions if you have a pacemaker.

Risks during the procedure to implant a pacemaker include:

• Puncture of the heart.
• Bleeding.
• Difficulty breathing.
• Irregular heart rhythms.
• Infection.
• Blood clot.
• Pacemaker malfunction.

What To Think About

In rare cases, people feel throbbing in the neck, chest fullness, or lightheadedness when the pacemaker sends out impulses. Talk to your doctor about what types of side effects you may expect from your pacemaker.

Rate-responsive pacemakers are often the ideal choice for active people. These pacemakers closely reproduce natural heart rhythms and are able to raise heart rate in response to physical activity. Your doctor can decide how fast the pacemaker should respond and how quickly your heart rate should return to a resting rate.

Strong electric or magnetic fields can interfere with your pacemaker. You can safely use most household and office equipment. And you can usually avoid electrical interference from magnetic or electrical sources by keeping certain things a few inches away from your pacemaker. You should completely avoid things like heavy electrical or industrial equipment.

You may walk through metal detectors (in airports or other security checkpoints) at a normal speed, but avoid standing near or leaning on these systems. Your pacemaker may set off a metal detector, but the security archways will not damage the device. Your doctor will give you a pacemaker identification card to carry at all times. Before you pass through a metal detector, tell the security guards that you have a pacemaker, and show them your device identification card.

If you have a pacemaker, you will not be able to have an MRI (magnetic resonance imaging) test. Before you have any tests or surgery, tell all of the health professionals involved in your care that you have a pacemaker. You may choose to wear a medical alert bracelet that says you have a pacemaker. Experts are trying to make pacemakers that can work safely during an MRI test.

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