Electrocardiogram Test
An electrocardiogram (EKG) records your heart's electrical activity to check how fast your heart beats, whether the rhythm is steady, and the strength and timing of electrical signals. It helps diagnose heart conditions like arrhythmia, heart attack, and heart failure.
What this test measures
An EKG measures the electrical signals that trigger your heartbeats. It shows how fast your heart is beating, whether the rhythm is steady or irregular, and the strength and timing of electrical signals passing through each part of your heart. It can also help measure the size and position of your heart's chambers.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Frequently asked questions
What does an EKG test show?
An EKG shows how fast your heart is beating, whether the rhythm is steady or irregular, and the strength and timing of electrical signals in your heart.
Is an EKG painful?
No, an EKG is a simple, painless, and quick test.
What conditions can an EKG help diagnose?
An EKG can help diagnose arrhythmia, cardiomyopathy, coronary artery disease, heart attack, heart failure, heart valve diseases, and congenital heart defects.
Do I need an EKG if I have no symptoms?
EKG tests are mainly for people with symptoms or a diagnosed heart condition. They are not generally used to screen people without symptoms unless they have an increased risk.
What happens if my EKG results are not normal?
If your results are not normal, it may be a sign of a heart condition. Your provider may need other tests before making a diagnosis.
Related lab tests
Sources
- MedlinePlus: Electrocardiogram — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.