Cardiac pacemaker
- 2. A pacemaker is a small device that is placed in the chest or abdomen to help or control abnormal heart rhythms. This device uses electrical pulses to prompt the heart to beat at a normal rate. Pacemakers are used to treat arrhythmias. Arrhythmias are problems with the rate or rhythm of the heartbeat. During an arrhythmia, the heart can beat too fast, too slow, or with an irregular rhythm. A heartbeat that is too fast is called tachycardia. A heartbeat that's too slow is called bradycardia.
- 3. During an arrhythmia, the heart may not be able to pump enough blood to the body. This can cause symptoms such as fatigue (tiredness), shortness of breath, or fainting. Severe arrhythmias can damage the body's vital organs and may even cause loss of consciousness or death. A pacemaker can relieve some arrhythmia symptoms, such as fatigue and fainting. A pacemaker also can help a person who has abnormal heart rhythms resume a more active lifestyle.
- 4. Heart has its own internal electrical system that controls the rate and rhythm of our heartbeat. In each heartbeat, an electrical signal spreads from the top of our heart to the bottom. As the signal travels, it causes the heart to contract and pump blood. Each electrical signal normally begins in a group of cells called the sinus node or sinoatrial (SA) node. First, the heart's two upper chambers, the atria contract. This contraction pumps blood into the heart's two lower chambers, the ventricles. The ventricles then contract and pump blood to the rest of the body. The combined contraction of the atria and ventricles is a heartbeat.
- 5. The pacemakers are recommended for many reasons. The most common reasons are bradycardia and heart block. Bradycardia is a heartbeat that is slower than normal. Heart block is a disorder that occurs if an electrical signal is slowed or disrupted as it moves through the heart. Heart block can happen as a result of aging, damage to the heart, some nerve and muscle disorders also can cause heart block, including muscular dystrophy.
- 6. A pacemaker consists of a battery, a computerized generator, and wires with sensors at their tips. The sensors are called electrodes. The battery powers the generator, and both are surrounded by a thin metal box. The wires connect the generator to the heart. A pacemaker helps to monitor and control the heartbeat. The electrodes detect the heart's electrical activity and send data through the wires to the computer in the generator. If the heart rhythm is abnormal, the computer will direct the generator to send electrical pulses to the heart. The pulses travel through the wires to reach the heart.
- 7. Newer pacemakers can monitor our blood temperature, breathing, and other factors. They also can adjust our heart rate to changes in our activity. The pacemaker's computer also records our heart's electrical activity and heart rhythm. The doctor will use these recordings to adjust our pacemaker so it works better for us. The doctor can program the pacemaker's computer with an external device. He or she doesn't have to use needles or have direct contact with the pacemaker.
- 8. The wires in a single-chamber pacemaker usually carry pulses from the generator to the right ventricle (the lower right chamber of the heart). The wires in a dual-chamber pacemaker carry pulses from the generator to the right atrium (the upper right chamber of the heart) and the right ventricle. The pulses help to coordinate the timing of these two chambers' contractions. The wires in a biventricular pacemaker carry pulses from the generator to an atrium and both ventricles. The pulses help to coordinate the electrical signaling between the two ventricles. This type of pacemaker is also called as cardiac resynchronization therapy (CRT) device.
- 9. Internal pacemaker An internal pacemaker is one in which the electrodes is fixed into the heart. It consists of myocardial or endocardial electrodes. It is intended for long-term use. The electronic circuitry and the power supply are implanted (internally) within the body. This kind of pacemaker is also called implantable pacemaker.
- 11. Transcutaneous pacing (also called external pacing) is a temporary means of pacing a patient's heart during a medical emergency. It is accomplished by delivering pulses of electric current through the patient's chest, which stimulates the heart to contract. An external pacemaker features exteriorized electrodes. This pacemaker is usually transistorized, miniaturized, battery-powered and patient-portable. It is recommended for short-term or temporary use.
- 12. Internal pacemaker It is used for permanent heart problems It requires surgery to implant the pacemaker If any problem arises in the electrical circuit or battery of pacemaker, a minor surgery is needed to replace it External pacemaker It is used for temporary heart problems It is located outside the body The battery can be replaced without surgery. There is no pain and swelling to the patient
- 14. Pacemaker surgery generally is safe. If problems may occur, they are: Swelling, bleeding, bruising, or infection in the area where the pacemaker was placed Blood vessel or nerve damage A collapsed lung A bad reaction to the medicine used during the procedure
- 15. The person having pacemaker, have to avoid close or prolonged contact with electrical devices or devices that have strong magnetic fields. Devices that can interfere with a pacemaker include: Cell phones and MP3 players (for example, iPods) Household appliances, such as microwave ovens High-tension wires Metal detectors Industrial welders Electrical generators These devices can disrupt the electrical signaling of the pacemaker and stop it from working properly.
- 16. Magnetic resonance imaging, or MRI Shock-wave lithotripsy to get rid of kidney stones Electrocauterization to stop bleeding during surgery