Pacemaker

• A pacemaker consists of a battery, a computerized generator, and wires. The generator sends the electrical pulses that correct or set your heart rhythm, and the wires carry pulses to and from various chambers of your heart and the generator.
• Pacemaker surgery is usually done in a hospital or special heart treatment laboratory. You will be given medicine to help you relax. The surgery takes just a few hours, but you will stay in the hospital overnight so your doctor can monitor your heart rhythm and make sure your pacemaker is working properly.
• Problems from pacemaker surgery are rare. Most people can return to normal activities within a few days.
• Your doctor may ask you to avoid any vigorous exercise or heavy lifting for a short period after your surgery. After you have fully recovered from surgery, discuss with your doctor how much and what kinds of physical activity are safe for you.
• Once you have a pacemaker, you have to avoid close or prolonged contact with electrical devices or devices that have strong magnetic fields. You also need to avoid certain medical procedures that can disrupt your pacemaker.
• Let all of your doctors, dentists, and medical technicians know that you have a pacemaker.
• Have your pacemaker checked regularly. Some pacemaker functions can be checked remotely through a telephone call or a computer connection to the Internet. Your doctor may ask you to come to his or her office to check your pacemaker.
• Pacemaker batteries have to be replaced every 5 to 15 years, depending on how active your pacemaker is. The wires of your pacemaker also may need to be replaced eventually. Your doctor can tell you whether you need to replace your pacemaker or its wires.

Who Needs a Pacemaker?

Doctors recommend pacemakers to patients for a number of reasons. The most common reason is when a patient’s heart is beating too slow or there are long pauses between heartbeats. A pacemaker may be helpful if:

• Aging or heart disease damages your sinus node’s ability to set the correct pace for your heartbeat. Such damage can make your heart beat too slow, or it can cause long pauses between heartbeats. The damage also can cause your heart rhythm to alternate between slow and fast.
• You need to take certain heart medicines (such as beta blockers), but these medicines slow down your heartbeat too much.
• The electrical signals between your heart’s upper and lower chambers are partially or completely blocked or slowed down (this is called heart block). Aging, damage to the heart from a heart attack, or other heart conditions can prevent electrical signals from reaching all the heart’s chambers.
• You often faint due to a slow heartbeat. For example, this may happen if the main artery in your neck that supplies your brain with blood is sensitive to pressure. In you have this condition, just quickly turning your neck can cause your heart to beat slower than normal. When that happens, not enough blood may flow to your brain, causing you to faint.
• You have had a medical procedure to treat an arrhythmia called atrial fibrillation. A pacemaker can help regulate your heartbeat after the procedure.
• You have heart muscle problems that cause electrical signals to travel through your heart muscle too slow. (Your pacemaker will provide cardiac resynchronization therapy for this problem.)

To decide whether a pacemaker will benefit you, your doctor will consider any symptoms you have of an irregular heartbeat, such as dizziness, unexplained fainting, or shortness of breath. He or she also will consider whether you have a history of heart disease, what medicines you’re currently taking, and the results of heart tests.A pacemaker won’t be recommended unless your heart tests show that you have irregular heartbeats.

Tests That Help Determine Whether You Need a Pacemaker

A number of tests are used to detect an arrhythmia. Your doctor may recommend some or all of these tests.

ECG (Electrocardiogram) This simple and painless test detects and records the electrical activity of the heart. An EKG shows how fast the heart is beating and the heart’s rhythm (steady or irregular). It also records the strength and timing of electrical signals as they pass through each part of the heart.

Holter Monitor A Holter monitor, also called an ambulatory ECG, records the electrical signals of your heart for a full 24- or 48-hour period. You wear small patches called electrodes on your chest that are connected by wires to a small, portable recorder. The recorder can be clipped to a belt, kept in a pocket, or hung around your neck.During the 24 or 48 hours, you do your usual daily activities and keep a notebook, noting any symptoms you have and the time they occur. You then return both the recorder and the notebook to your doctor to read the results. Your doctor can see how your heart was beating at the time you had symptoms.The purpose of a Holter monitor is to record heart signals during typical daily activities and while sleeping, and to find heart problems that may occur for only a few minutes out of the day.

How Does a Pacemaker Work? A pacemaker consists of a battery, a computerized generator, and wires with electrodes on one end. The battery powers the generator, and a thin metal box surrounds both it and the generator. The wires connect the generator to the heart. The pacemaker’s generator sends the electrical pulses that correct or set your heart rhythm. A computer chip figures out what types of electrical pulses to send to the heart and when those pulses are needed. To do this, the computer chip uses the information it receives from the wires connected to the heart.

It also may use information from sensors in the wires that detect your movement, breathing, or other factors that indicate your level of physical activity. That way, it can make your heart beat faster when you exercise.The computer chip also records your heart’s electrical activity and heart rhythms. Your doctor will use these recordings to set your pacemaker so it works better at making sure you have a normal heart rhythm.

Your doctor can program the computer in the pacemaker without having to use needles or directly contacting the pacemaker.The wires in your pacemaker send electrical pulses to and from your heart and the generator.