This page was reviewed under our medical and editorial policy by
Faizi A. Jamal, MD, Cardiologist, City of Hope | Duarte
This page was reviewed on June 1, 2023.
An electrocardiogram (EKG) is a simple, noninvasive test that shows how well your heart functions. It measures the electrical signals that travel through your heart with each beat.
Before beginning cancer treatment, your doctor may order an EKG to check on your heart’s strength. Your doctor may also order an EKG during and after cancer treatment to monitor for possible damage.
The test is performed using a machine known as an electrocardiograph, which records your heart’s electrical activity and prints it out on a graph for the doctor to see. A normal heart beats 60 to 100 times a minute. Your doctor looks at the rhythm and wave pattern on the graph for any irregularities.
Both of these abbreviations refer to an electrocardiogram. EKG, based on the German spelling (elektrokardiogramm), is often preferred to avoid confusion with another test, EEG (electroencephalogram), which measures brain waves.
An EKG is typically performed in your doctor’s office or a hospital and lasts about 10 minutes.
The test is done with you lying flat on an examination table. What to expect:
When scheduling your appointment, be sure to discuss:
On the day of your appointment:
Cancer treatment, especially chemotherapy and radiation, may affect the heart. An EKG shows whether the patient has:
Because it’s noninvasive and simple, there’s little risk to having an EKG. An EKG records electricity, but it doesn’t send electricity through your body. Your skin may be irritated where the electrodes are attached, but that shouldn’t last long.
Your doctor may order an echocardiogram (echo) as well as an EKG to monitor your heart. They are often done at the same time.
An echo is an ultrasound of the heart. Like an EKG, an echo is painless and noninvasive. It uses a machine that measures sound waves that “echo” back. An echo may identify: