Pacemakers.Pdf

Pacemakers

Normally, the heart is signaled to contract, or squeeze, by an electrical impulse that starts in the sinus node at the top of the right atrium. The impulse then travels through over the job of the heart’s own the heart’s “wires” to the muscles electrical system and prevent slow of the lower chambers of the heart heart rates. Although they weigh (right and left ventricles), telling only an ounce and are the size of a them to contract and cause a large wristwatch face, a pace - heartbeat. This natural system maker contains a computer with helps the heart pump in an effi - memory and electrical circuits, a cient rhythm. A problem with any powerful battery (generator), and part of this system, though – either special wires called “leads.” The the heart’s natural “pacemaker” or generator creates electrical im - machine. The leads touch the the wires carrying the impulses – pulses that are carried by the heart muscle on one end, and are can cause a slow heart rate. An ar - leads to the heart muscle, signal - connected to the pacemaker tificial pacemaker may be needed, ing it to pump. generator on the other end. The to reset the heart to the right pace pacemaker is programmed to Getting a pacemaker does not re - and make sure blood and oxygen send signals to the heart, and set - quire open-heart surgery — the are pumped to the brain and other tings can be changed at any time. procedure usually takes only about parts of the body. Routine monitoring, sometimes two hours. The pacemaker genera - even by phone, makes sure the What is a Pacemaker? tor is implanted in a small pocket pacemaker is working properly. Artificial pacemakers are devices made under the skin. The leads The battery in the generator lasts that are implanted into the body are usually placed in a vein near 5-10 years and must be replaced just below the collarbone, to take the collarbone, and then moved to when it runs out. the heart with the help of an X-ray

did you The development of the silicon transistor and its first commercial availability in 1956 was the know pivotal event which led to rapid development of practical cardiac pacemaking. The body of a pacemaker measures about 3-4 centimeters, about the size of two silver dollars stacked on top of each other.

Types of Pacemakers When are Pacemakers Used? Single Chamber Pacemakers Pacemakers may be prescribed for Take Note: have one wire that is placed in the a number of conditions, including: Ⅲ Full-contact sports can damage a right upper chamber (atrium) or pacemaker. Bradycardia – a condition in which lower chamber (ventricle). Ⅲ Magnetic Resonance Imaging the heart beats too slowly, causing (MRI) tests employ powerful mag - Dual Chamber Pacemakers have symptoms such as fatigue, dizzi - nets to create images. If you are two wires, one in the atrium and ness, or fainting spells. scheduled for an MRI test, you one in the ventricle. Atrial fibrillation – a common heart should make certain your doctor Biventricular Pacemakers have rhythm disorder in which the heart knows you have a pacemaker. three wires, one in the right atrium, beats too fast and chaotically. Ⅲ Electronic security systems, one in the right ventricle and a People with atrial fibrillation can such as those common in airports, third in the left ventricle. These also sometimes have slow can pose problems if exposure is more complicated pacemakers rhythms. Medicines used to control prolonged. Passing through such take more time to implant, and can atrial fibrillation may result in slow systems, even several times, does be used to improve pumping in rhythms, which can be treated by not pose a threat. patients with heart failure. pacemakers. Ⅲ Microwave ovens, cellular Rate Responsive Pacemakers Heart failure – a condition in which phones, and electric blankets do adjust the heart rate to a patient’s the heartbeat is not strong enough to not, as myth might have it, affect level of activity. They pace faster carry a normal amount of blood and pacemaker functioning. when a patient is exercising and oxygen to the brain and other parts slower when a patient is resting. of the body. A special pacemaker can be programmed to increase the force of heart muscle contractions. This is called “biventricular pacing” or “resynchronization” therapy.