The Electrocardiogram (EKG): A Medical Assistant’s Guide


Medical assistants have a broad range of responsibilities, but among the most essential is performing diagnostic tests. It’s an exciting role using advanced equipment and cutting-edge technology to look into the human body in ways that were never thought possible. One test, the electrocardiogram or EKG, gives doctors critical information about the function of the heart, and it’s one in which medical assistants play an important part.

What is an Electrocardiogram?

Invented in 1903 by Dutch physician , the EKG creates a tracing of the electrical activity in the heart. Like any other muscle, the heart requires electrical impulses to contract. As voltage flows in a coordinated pattern between the four chambers of the heart, the upper atria and the lower ventricles, the EKG captures its movement and can diagnose many heart conditions. It’s performed as both a screening test and when patients have symptoms suggesting cardiac disorders from a heart attack to an electrolyte imbalance.

How is an EKG performed?

Electrocardiograms are performed with machines called electrocardiographs. Leads connected to pads attached to the patient’s body measure electrical activity as it courses through the heart. It’s a non-invasive test completed by a medical assistant in nearly any setting.

Types of EKGs

A standard EKG uses 12-leads, each lead measures electrical impulses from a distinct perspective, giving doctors a view of how the heart is functioning from two different angles, horizontal and vertical.

Usually done with the patient at rest, it’s painless and takes only ten minutes to perform. A more detailed version, called a signal-averaged EKG, averages results over a longer period of time and helps diagnose abnormal heartbeats that may not occur continually.

Similarly, doctors may order a portable EKG for patients who have symptoms such as palpitations that happen only on occasion or under specific circumstances. Mobile EKG devices, known as Holter monitors, can be worn from a few days to a few weeks, catching abnormalities a shorter EKG can miss.

Today’s devices are as small as a deck of cards and worn discreetly as patients go about their regular routine. Wireless versions that send irregular readings to the doctor in real-time are the new standard.

EKGs are also part of a more comprehensive evaluation of cardiac health called a stress test. Stress tests show how a patient’s heart functions during strenuous exercise. Patients walk on a treadmill or ride a stationary bike while an electrocardiograph measures how their heart responds. For patients who can’t exercise, medications, such as dopamine, that simulate the heart’s response to activity can be used instead. Stress tests require additional medical supervision and they are rarely done by medical assistants alone.

Limited EKGs using less than 12 leads are used for routine ambulance transports and to monitor specific, known conditions.

What Do Doctors Learn from EKGs?

An electrocardiogram is just one of many tests used to evaluate heart function, but it’s among the most diagnostic. By examining waveform patterns, doctors can detect dysrhythmias, ischemia, hypertrophic cardiomyopathy, electrolyte imbalances, heart attacks and myocardial infarctions.

Dysrhythmias — abnormalities in heart rate or rhythm including tachycardia, bradycardia and atrial fibrillation

Ischemia — reduced blood supply to the cardiac muscle causing chest pain

Hypertrophic Cardiomyopathy — thickening of the heart walls in response to heart failure or hypertension

Electrolyte Imbalances — high or low levels of potassium, calcium or magnesium — ions that can affect how the heart works

Heart Attacks, or Myocardial Infarctions — the death of heart muscle caused by a blockage in a coronary artery

Doctors routinely order EKGs to rule out heart disease as the cause of common symptoms such as:

  • Chest pain
  • Shortness of breath
  • Dizziness
  • Fatigue

Advantages to an EKG

Compared to other types of tests performed to check heart function, EKGs have clear advantages. These advantages include a quick response, portability, non-invasiveness, painless, cost-and effectiveness.

They’re Quick and Portable

In less than fifteen minutes, including preparation time, an EKG can diagnose a heart attack, allowing swift and potentially life-saving intervention. And because they’re portable, ambulance crews can transmit readings to a hospital in route, saving valuable time.

They’re Non-Invasive

EKGs measure electrical activity in the heart using only external electrodes. In contrast to cardiac catheterization, a technique in which a thin tube is guided into the coronary arteries from a vein or artery in the arm, neck or groin, EKGs require no medication and have no significant threat of complications.

They’re Painless and Easy

The more complicated tests are, the more likely patients are to avoid them. EKGs require no preparation or post-test limitations, and they don’t hurt a bit. Most can be performed in a physician’s office, making them especially convenient.

They’re Cost-Effective

Prices vary, but the average cost of an EKGs ranges between $100 to $1200. That’s half the cost of similar non-invasive tests and thousands less than cardiac catheterization. Many insurers require EKGs before authorizing additional testing. EKGs done by a medical assistant in a physician’s office are among the least expensive.

The Medical Assistant’s Role in EKGs

Although the 12-lead EKG is the most common, medical assistants may also participate in stress testing or assist patients with the use of a Holter monitor. Understanding why each type of EKG is performed and how to help is a must.

Medical assistant training programs teach all the skills necessary to complete an electrocardiogram from start to finish, including pretest preparation, patient education and consent, pre-screening, patient preparation, testing and aftercare

Pretest Preparation

Medical assistants are responsible for sanitizing the exam room and performing quality control checks on equipment before getting started. Because an electrocardiograph is an electrical device, instruments that produce current could interfere with its function, so they should be turned off whenever possible.

Ensuring the exam space is both functional and comfortable encourages patients to relax and makes the process easier. A busy cardiology practice may have dozens of EKGs scheduled each day, so efficiency is important.

Patient Education and Consent

Before performing an EKG, medical assistants explain how the test will be performed and verify that they have the patient’s consent to proceed. Getting the best results on an EKG requires patients to remain still, so talking about it in advance demystifies the process and clarifies expectations.


Medical assistants pre-screen patients for physical limitations or other factors that could impact testing. Making accommodations in advance improves patient comfort and ensures the best results.

Patient Preparation

Physical preparation for an EKG is simple, but each step contributes to optimal results.

Medical assistants help by:

  • Reminding patients to remove jewelry, watches and metal body piercings that can interfere with the test
  • Offering loose-fitting garments that makes electrode placement easier if their clothing is tight
  • Assisting patients into the exam chair or table
  • Ensuring patient privacy
  • Shaving hair and cleansing the skin where electrodes will be applied

EKG Testing

EKG testing requires the knowledge, skill and clinical judgment of a trained support professional such as a medical assistant. The steps are easy:

Step #1 – Electrode pads are placed on the patient’s body. Once placed, the color-coded leads that transmit the reading are attached. Firm and consistent application makes it easier for physicians to notice unusual variations from test to test while avoiding placement over bones or irritated skin decreases troublesome artifacts.

Step #2 – Once the electrocardiograph is on and prepared to take an active reading, the medical assistant cues the patient to take a deep breath and remain still until told the test is complete. If artifacts are significant, the test may need to be redone.

Step #3 – Medical assistants don’t interpret EKGs, but with experience, they learn which irregularities may indicate an impending health crisis. Benign results are entered into the medical record without fanfare, but unusual findings should be reported to a doctor immediately. Once, EKG results were printed on paper strips that had to be securely mounted in a chart, but today’s digital devices are paperless.


After the test, the medical assistant takes off the electrodes and helps the patient remove the pads. Persons with mobility challenges may need an extra hand. And before the client departs, they should take a few minutes to explain when the doctor will review results and who to contact if they develop concerning symptoms.

The exam room is then prepared for the next patient. Used supplies are carefully disposed of per OSHA and infection control protocols, and surfaces are sanitized. The environment is fast-paced.

Final Thoughts

Learning to perform diagnostic tests, such as EKGs, takes education and practice, but it’s among the most tangible and rewarding ways medical assistants make a difference in the lives of the patients they serve.

Did learning about a medical assistant’s role in EKGs interest you? Meridian College offers hands–on Medical Assistant training from experienced school faculty who know how to prepare you for the daily challenges you’ll face on the job. From assisting doctors with patients to important administrative tasks, our experienced Medical Assistant program teachers will train you for a rewarding new career.

Contact Meridian College today to learn more about becoming a medical assistant.