Doctors can often make a preliminary diagnosis of heart failure by medical history and careful physical examination.
A thorough medical history may identify risks for heart failure that include:
- High blood pressure
- Abnormal cholesterol levels
- Heart disease or history of heart attack
- Thyroid problems
- Lifestyle factors (such as smoking, alcohol use, and drug use)
The following physical signs, along with medical history, strongly suggest heart failure:
- Enlarged heart
- Abnormal heart sounds
- Abnormal sounds in the lungs
- Swelling or tenderness of the liver
- Fluid retention in legs and abdomen
- Elevation of pressure in the veins of the neck
Both blood and urine tests are used to check for problems with the liver and kidneys and to detect signs of diabetes. Lab tests can measure:
- Complete blood counts to check for anemia
- Kidney function blood and urine tests
- Sodium, potassium, and other electrolytes
- Cholesterol and lipid levels
- Blood sugar (glucose)
- Thyroid function
- Brain natriuretic peptide (BNP), a hormone that increases during heart failure. BNP testing can be very helpful in correctly diagnosing heart failure in patients who come to the emergency room complaining of shortness of breath (dyspnea).
An electrocardiogram (ECG) is a test that measures and records the electrical activity of the heart. It is also called an EKG. An electrocardiogram cannot diagnose heart failure, but it may indicate underlying heart problems. The test is simple and painless to perform. It may be used to diagnose:
- Previous heart attack
- Abnormal cardiac rhythms
- Enlargement of the heart muscle, which may help to determine long-term outlook
- A finding called a prolonged QT interval may indicate people with heart failure who are at risk for severe complications and therefore need more aggressive therapies.
A completely normal ECG means that heart failure is unlikely.
Review Date: 05/04/2011
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.