An electrocardiogram, or EKG, is a simple test that doctors use to measure the electrical activity of the heart. This helps them look for underlying heart conditions.

Sometimes, an abnormal EKG reading is actually just a normal variation in a person’s heart rhythm. In other cases, it may be due to an underlying condition of the heart or a reaction to a medication the person is taking.

An EKG reading is a helpful diagnostic tool. Once a doctor has identified the underlying condition, they can suggest appropriate treatment.

EKG results

EKG results being held by person
An EKG can help visualize the electrical activity of the heart.

To many people, an EKG is just a series of lines. However, each line corresponds to an electrical signal sent from the heart.

Doctors know how to read and interpret these lines, which gives them a sense of the overall state of the heart.

The administering doctor or healthcare professional will attach electrodes to a person’s skin, typically at 10 different points around their chest and on the limbs.

Each heartbeat sends out an electrical impulse. These electrodes pick up this impulse and record the activity in a wave form on a graph.

All of this happens in the blink of an eye, which is why an EKG is so important. An EKG can catch all of these tiny details and record them for a doctor to analyze.

What causes an abnormal EKG?

An abnormal EKG means that there is something unexpected in the EKG reading. This is not always a sign of an unhealthy heart.

For instance, in 2015, researchers found that competitive sports athletes regularly had abnormal EKG readings.

The researchers indicated that the majority of these results were harmless and due to the person’s adaptation to exercise. However, they still called for thorough screening to check for any other risk factors.

With this in mind, an abnormal EKG reading could appear for many reasons, including:

Irregular heart rate

An EKG will pick up any irregularities in a person’s heart rate.

The human heart typically beats at around 60–100 beats per minute. A heart that beats any faster or slower than this may indicate an underlying issue. A doctor will want to run additional tests to find the underlying cause.

Irregular heart rhythm

Although it may vary slightly between each person, each heart keeps a steady rhythm. A person may physically feel changes in this rhythm, such as skipped heartbeats or feeling as though the heart is fluttering.

An EKG will help doctors see how and where the heart is beating out of rhythm but will only be able to record the irregularity if it happens during the test.

Since this is unlikely, doctors may recommend using a Holter monitor, which monitors the heart’s activity for 24 hours or longer. This gives doctors a better opportunity to catch the irregularity.

Abnormalities in the shape of the heart

An EKG gives doctors an idea of how hard the heart is working in each specific area. An abnormal EKG result can be a sign that one region or section of the heart is larger or thicker than the others.

A thickened heart could mean that the heart is working too hard to pump blood. This may be due to a congenital or acquired heart condition.

Electrolyte imbalances

Electrolyte minerals are important for overall health, but they also play a role in heart health and may even cause an abnormal EKG.

Electrolytes conduct electricity in the body and help keep the heart rate and rhythm consistent. An imbalance in electrolyte minerals such as potassium, sodium, calcium, or magnesium may cause an abnormal EKG reading.

Medication side effects

Taking certain medication may cause abnormal EKG results.
Taking certain medications may cause abnormal EKG results.

Some medications may cause an abnormal EKG reading. Anyone who is getting an EKG should discuss any medications they are taking with a doctor. It may also help to check the list of side effects provided on the packaging.

Some medications that help balance the heart rhythm may actually cause abnormal heart rhythms in some people. Such medications include certain beta-blockers and sodium channel blockers.

If a doctor thinks that the type of medication a person is taking may be causing their symptoms, they may suggest alternatives and then do a follow-up EKG to see how the person responds to the new medication.

High blood pressure

Other aspects of heart disease may lead to an abnormal EKG. For example, people with high blood pressure are more likely to have an abnormal EKG reading.

Heart attack

Sometimes, an abnormal EKG result may be a sign of a serious issue, such as a heart attack.

When a person has a heart attack, the heart can lose its fresh supply of blood, which can cause tissue damage and even cell death.

Damaged tissue will not conduct electricity as well as healthy tissue, which could cause the abnormal EKG reading.


Treatment for an abnormal EKG depends on the underlying issue. If the doctor suspects the abnormal EKG is a result of normal variances in the human heart, they may recommend no treatment at all.

If a certain medication is causing the abnormal readings, they may recommend an alternative. If the doctor suspects that a person has an electrolyte imbalance, they may suggest fluids or medications that contain electrolytes.

Other issues may require more individualized treatments. An arrhythmia may or may not require treatment. Most arrhythmias pose little to no risk to the person, as they may not cause symptoms or interfere with the heart’s function.

On the other hand, some arrhythmias may interfere with the heart’s ability to pump blood. If a heart is having trouble keeping a steady rhythm, a doctor may recommend medications or ask the person to wear a pacemaker to help restore the heart’s rhythm.

Anyone having a heart attack will need emergency medical treatment. The person may also need to undergo surgeries such as angioplasty to keep the blood flowing and reduce damage to the tissues.

When do you need an EKG?

Man having an electrocardiogram or EKG in hospital
A doctor may recommend an EKG to diagnose or monitor heart conditions.

Many people will get an EKG reading at some point in their lives, often due to experiencing common symptoms such as chronic chest pain, shortness of breath, or a rapid pulse.

Doctors may also regularly use EKGs to check on people with diagnosed heart disease.

Another reason to get an EKG is experiencing heart palpitations or arrhythmia. A person may feel as though their heart skips a beat, that their heart is fluttering, or that it is beating very strongly.

Doctors may recommend an EKG here to check for any underlying issues. They may order additional tests depending on the results.


An EKG is a risk-free and noninvasive procedure. It does not send electricity into the body and will not cause any pain.

It is an important tool for diagnosing conditions affecting the heart. Most people will undergo an EKG at some point.

Although having an abnormal EKG can seem scary, it is important to understand that it is just one part of a proper diagnosis. Many things can cause an abnormal EKG, and not all of them are dangerous.

A doctor can recommend further tests to diagnose the underlying cause of a person’s symptoms and EKG results.