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What is an EKG Machine and How Does it Work?

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EKG is short for electrocardiogram and is called both an ECG and an EKG, as abbreviations for the word electrocardiogram (derived from the Greek electro for electric, kardio for heart, and graph for “to write”) and the German word electrokardiogramm. An EKG machine interprets and records the electrical impulses of the heart for diagnostic purposes. It is not a form of treatment for heart conditions, but can help doctors diagnose and determine the proper treatment for a particular heart condition by taking a closer look at the heart and its activity.

All About the Electrocardiogram

An EKG records the heart’s own electrical impulses to create an electrocardiograph, a reading that helps physicians learn more about the heart. The procedure itself is called an electrocardiogram. Since the machine simply uses the heart’s natural electricity to record data, the procedure is completely noninvasive. The machine and the procedure are both fairly simple, but they have had huge implications for the field of cardiology.

An electrocardiogram does the following:

  • determines the rate and regularity of heartbeats
  • measures the size and positioning of the chambers
  • evaluates damaged and diseased tissue or other physical irregularities
  • monitors any surgical repairs, pacemakers, or effects of drugs used to treat existing heart conditions

An EKG does not measure the heart’s ability to pump blood.

An EKG is not usually performed as a preventative measure, and it is only utilized to diagnose or rule out the presence of diseases, disorders, and other irregularities. However, EKG machines are often found in general practice clinics, in addition to seeing regular use in ambulances, emergency rooms, hospitals, and cardiology centers.

How an EKG Machine Works

EKG setups are fairly small in size and are considered portable. They consist of a small box that houses the machine, which is connected to a number of electrodes. The impulses picked up by the electrodes are recorded in pairs, and each pair is known as a lead. The different machines are referred to as 3-lead, 5-lead, and 12-lead EKGs.

Each lead views the heart from a different angle. 3 and 5-lead EKGs are considered portable, record limited heart activity, and are primarily used to monitor a patient’s heart during surgery or on the way to the hospital in an ambulance. 12-lead machines look at the heart from twelve different angles and provide the type of readings necessary to diagnose and monitor patients with heart conditions of varying degrees.

In a 12-lead EKG, six electrodes are attached to the skin on the chest around the heart. Four more electrodes are added, one on each arm and leg. The ten electrodes combine in twelve different ways to read twelve different angles on the heart. When the heart depolarizes with each heartbeat, the electrodes sense the tiny electrical impulses on the skin that are created as a result. The impulses travel back to the machine where they are interpreted and printed on a graph.

Each heart muscle cell has a negative charge at rest, but moves closer to a neutral charge with each beat, called depolarization. Each pair of electrodes records the changes in voltage created between the two when the heart depolarizes with each beat. A healthy heart will print out an orderly wave of progression with each heart beat, while a heart with diseased or damaged tissue will show certain irregularities in the heart’s rhythm, size, or position.

How EKG Helps Heart Patients and Doctors

An EKG is used to record the heart’s activity in patients with the following conditions or symptoms:

  • Heart murmur – Sounds made by the heart due to insufficient blood flow. Heart murmurs are fairly common and often considered normal, but can sometimes indicate a blocked or narrowed valve, artery, or other passage.
  • Arrhythmia – Irregular heartbeats caused by abnormal electrical activity, which can cause the heart to beat too slowly, quickly, or irregularly.
  • Myocardial infarction – Also known as a heart attack, the heart stops beating due to complete blockage of blood flow to the heart, creating enough oxygen deprivation to stop the heart.
  • Seizures and syncope – Patients experiencing unexplained seizures or fainting may be tested with an EKG to rule out any heart dysfunction as the culprit.

While an electrocardiogram cannot stop or heal any of the above conditions, it does give doctors the ability to accurately diagnose both early and advanced heart conditions, regularly monitor the results of treatments, and make appropriate changes/recommendations for therapy, medicine, and surgery.