The 'Natural' Pacemaker

• In order to appreciate the function of a pacemaker, it is important to understand what responsibility it fulfills. In a healthy person, the sinoatrial node (or SA node) causes the heart to beat in a regular rhythm. This 'natural' pacemaker is a small clump of specialized cells located in the upper chamber of the heart, near the right atrium.
  
  The heart is only able to beat rhythmically when electrical impulses initiating from the SA node travel along a defined path, reaching the lower chambers of the heart, known as the ventricles. In individuals who have a defective natural pacemaker, the heart muscles are not stimulated to contract and relax rhythmically, leading to irregular heart rates.
  
  

Form & Function

• A pacemaker is battery-operated, and consists of a computerized generator, and wires with sensors, known as electrodes. The generator is powered by the battery, and the wires run from the generator to the heart. The entire unit is covered in a thin metal casing. The pacemaker's electrodes detect irregularities in the heart's electrical activity, and send the information to the computerized generator.
  
  In monitoring the heart rate, when the pacemaker identifies irregularities, it tells the generator to send electrical pulses, in sync with normal heart rates. Once the electrical pulses reach the muscles, the heart beats in a normal pattern. Over time, a medical professional may calibrate the device for optimal performance, based on electrical activity and heart rhythm readings from the tiny computer in the device.
  
  

Arrhythmia Consequences & Pacemaker Benefits

• Irregular heartbeats are categorized as either tachycardia, in which the heart beats too fast, or bradycardia, in which the heart beats too slow. In either of the cases, the heart is unable to provide the body sufficient amounts of blood in time, leading to fatigue, shortness of breath and even fainting. In extreme arrhythmias, the body's vital organs may be damaged. A pacemaker reinstates regular heart rate during arrhythmia by mimicking the SA node, stimulating the heart muscles in regular patterns. Pacemakers not only relieve symptoms associated with arrhythmia, but also enable sufferers to resume a healthier, more normal lifestyle.
  
  

Temporary Pacemakers

• Temporary pacemakers are designed to treat short-lived problems with heart rate. Such abnormalities in rhythm may be caused by a heart attack, surgery or as a reaction to medicine overdose. A temporary pacemaker may also be used for an emergency, helping to control heart rate in a severe arrhythmia, until a permanent pacemaker is implanted. Those fitted with a temporary pacemaker have to stay at the hospital as long as the device is in place.
  
  

Innovation

• Advancements in medical technology have enhanced pacemaker function and capabilities. Modern units are versatile devices, able to monitor a range of bodily functions, including breathing rate, blood temperature and other factors. The pacemaker then processes these inputs and adjusts its function, according to changes in activity.