What Can an EKG Detect?

Reviewed by AIMS Education Staff 

December 9, 2021

The electrocardiogram — commonly abbreviated EKG or ECG — is a standard diagnostic tool that clinicians have used to evaluate patients with cardiac distress since the early 20th century. Since then, electrocardiograms have been used to diagnose life-threatening heart conditions and save people's lives. EKGs track and record the electrical activity in your heart to ensure it's healthy and functioning correctly.

Learning to interpret an EKG is a valuable skill for health care providers with varying levels of training and expertise. This guide will explain EKG tests and how they're used to detect heart disease.

What Is an EKG Test?

Your pacemaker cells create electrical impulses that travel across the heart to trigger a heartbeat. Doctors use electrocardiogram or EKG tests to measure these electrical impulses and determine the health of your heart. It's a noninvasive and painless method that shows your heart rate and the size and position of your heart. 

There are EKG machines in most hospitals, ambulances, and emergency rooms. Clinicians use them to evaluate patients during routine checkups, health crises, and before surgery. A doctor will place electrodes at strategic locations on your chest and limbs to detect and record the electrical activity. 

Clinicians review the rhythm and strength of the electrical pulses for abnormalities, looking for heart rates that are too slow, too fast, or skip a beat. They also look for blocked or restricted arteries, swelling, and signs of a previous heart attack. An irregular EKG is often a sign of heart disease or damage.


How Does an EKG Test Work?

In the human body, muscle and nerve cells communicate through chemical and electrical signals from the sinoatrial node, also referred to as the natural pacemaker of the heart. These signals travel across your heart muscle tissues in the form of tiny electrical impulses. An EKG can detect, measure, and plot these signals on a graph to determine the health of your heart. 

Whether you're in a doctor's office, outpatient clinic, or ambulance, the nurse or technician will follow a similar process. Here's what you can expect during an EKG scan: 

  1. You'll remove your shirt or change into a hospital gown, so the doctor can easily access your upper body. 
  2. The healthcare provider may shave your body in a few areas so the electrodes will stick to your skin.
  3. Then you'll lie down on the exam table while the nurse or technician applies 10 electrodes — small sticky sensors — to your chest, arms, and legs. 
  4. During the test, you'll lie as still as possible so the machine can capture accurate results. 
  5. The electrodes connect to wires that transmit your heart's electrical activity to a computer. The computer monitor displays your heart's activity and will record the results digitally or print them on paper. 
  6. When the test is complete, a doctor will review the results for signs of heart disease.

How Long Does an EKG Take?

Getting an EKG is a quick and easy process. Once you're on the exam table and the electrodes are attached, the EKG test itself only takes about three minutes. The process is entirely painless, though some people experience skin irritation when the technician removes the electrodes. 

Most people can resume their normal activities after the test is complete. Your doctor may take several days to contact you with your EKG test results. If your scan looks abnormal, you may need further diagnostic testing. 


Why Is an EKG Test Performed?

A doctor may prescribe routine EKG tests if you have an increased risk of heart disease, a pacemaker, or take medication for an existing heart condition. While the procedure is entirely safe, the American Heart Association advises against mass EKG testing for younger people, as fatal heart conditions are rare in teens and young adults. Cardiac conditions are more common in middle-aged and older adults, especially those with a family history of heart disease.

 A doctor may also order an EKG scan when a patient presents the following symptoms: 

  • Irregular pulse
  • Increased heart rate
  • Shortness of breath
  • Heart palpitations
  • Tightness and pain in the chest 
  • Dizziness 
  • Confusion 
  • Muscle weakness 
  • Fatigue 


What Problems Can an EKG Detect?

An EKG can help determine the following heart conditions. 

1. Arrhythmia

Arrhythmia refers to abnormal electrical impulses in the heart. This condition includes any changes in your heartbeat compared to a healthy electrical sequence. Arrhythmia could mean that your heart is beating at an abnormal speed or irregular intervals. People with arrhythmia may feel like their heart is racing or fluttering. While not all arrhythmias are dangerous, some can disrupt blood flow which could damage your brain, lungs, and other organs. 

2. Heart Attack

A heart attack occurs when blood is cut off from the heart muscle. A buildup of plaque in the arteries is often the cause of the blockage. Heart attacks can cause varying levels of chest pain, shortness of breath, nausea, fatigue and discomfort in one or both arms. An EKG can confirm if you're currently having a heart attack or if you've had one in the past.  

3. Coronary Artery Disease

The most prevalent cardiac illness in the nation is coronary artery disease (CAD). It's caused by a buildup of plaque that narrows the arteries that carry blood to the heart. CAD is the leading cause of heart attacks, heart failure, and death in the U.S. An EKG can help identify CAD, so patients can seek treatment before it develops into a life-threatening emergency.  

4. Cardiomegaly 

Cardiomegaly, more commonly known as an enlarged heart, refers to temporary or permanent swelling of the heart muscle. An enlarged heart is a symptom of other cardiac issues like CAD, arrhythmia, heart valve problems, weakening of the heart muscle, and other medical conditions. An EKG can help identify cardiomegaly and other cardiac diseases that may have caused the swelling so patients can seek the appropriate treatment.

5. Aortic Aneurysms

An aortic aneurysm is a weak point or bulge that forms in the walls that line the aorta. The aorta is a major blood vessel that delivers blood from the heart to the rest of the body. If an aneurysm bursts, blood can leak from the artery causing a life-threatening emergency. An EKG can help diagnose and monitor aortic aneurysms before they burst.

Discover AIMS Education's Cardiac Monitor Technician Program

Millions of EKGs are performed yearly in the U.S. to help doctors diagnose patients with heart disease. Cardiac Monitor Technicians can help patients detect life-threatening cardiac disorders before it's too late. 

At AIMS Education, you can complete the Cardiac Monitor Technician program to help connect patients with life-saving treatments for their heart conditions. Our high-quality instructors and hands-on training will help you develop the skills you need to earn a job at a hospital, nursing home, or cardiologist's office.

After completing the Cardiac Monitor Technician program, you'll be prepared to conduct an EKG test as well as perform stress testing, ambulatory monitoring, and rhythm analysis. If you're seeking a career helping others through medical testing, learn more about the program at AIMS Education today!