- A Visual Guide to Heart Disease
- Medical Illustrations of the Heart Image Collection
- Take the Heart Disease Quiz!
- Patient Comments: Electrocardiogram (ECG or EKG) - Results
- Patient Comments: Electrocardiogram (ECG or EKG) - Test
- Patient Comments: Electrocardiogram (ECG or EKG) - Diagnosis
Quick GuideHeart Disease: Causes of a Heart Attack
What are the limitations of the ECG (EKG)?
- The EKG is a static picture and may not reflect severe underlying heart problems at a time when the patient is not having any symptoms. The most common example of this is in a patient with a history of intermittent chest pain due to severe underlying coronary artery disease. This patient may have an entirely normal EKG at a time when he or she is not experiencing any symptoms. In such instances, the EKG as recorded during an exercise stress test may reflect an underlying abnormality while the EKG taken at rest may be normal.
- Many abnormal patterns on an EKG may be non-specific, meaning that they may be observed with a variety of different conditions. They may even be a normal variant and not reflect any abnormality at all. These conditions can often be sorted out by a physician with a detailed examination, and occasionally other cardiac tests (for example, echocardiogram, exercise stress test).
- In some instances, the EKG may be entirely normal despite the presence of an underlying cardiac condition that normally would be reflected in the EKG. The reasons for this are largely unknown, but it is important to remember that a normal EKG does not necessarily preclude the possibility of underlying heart disease. Furthermore, a patient with heart symptoms can frequently require additional evaluation and testing.
Medically reviewed by Robert J. Bryg, MD; Board Certified Internal Medicine with subspecialty in Cardiovascular Disease
"Basic ECG test" UptoDate. Updated July 15, 2016