Heart Failure Diagnosis

To diagnose heart failure, your doctor will first ask you questions about your symptoms and medical history. Your doctor will want to know:

• If you have any other health conditions such as diabetes, kidney disease, angina, high blood pressure or other heart problems.
• If you smoke.
• If you drink alcohol and how much you drink.
• What medications you are taking.

Your doctor will also perform a complete physical exam. Your doctor will look for signs of heart failure as well as any other illnesses that may have caused your heart to weaken.

Your doctor may also order tests to determine the cause and severity of your heart failure. These include:

• Blood tests. Blood tests are used to evaluate kidney and thyroid function as well as to check cholesterol levels and the presence of anemia. Anemia is a blood disorder that occurs when there is not enough hemoglobin (the substance in red blood cells that enables the blood to transport oxygen through the body) in a person's blood.
• B-type natriuretic peptide (BNP) blood test . BNP is a substance secreted from the heart in response to changes in pressure that occur when heart failure develops and worsens. The level of BNP in the blood increases when heart failure symptoms worsen, and decreases when the heart failure condition is stable. The BNP level in a person with heart failure -- even someone whose condition is stable -- is higher than in a person with normal heart function.
• Chest X-ray. Chest X-ray shows the size of your heart and whether there is fluid build-up around the heart and lungs. 
• Echocardiogram. This test (often called an "echo") shows a graphic outline of the heart's movement. During an echo, a wand is placed on the surface of your chest. This wand sends ultrasound waves that provide pictures of the heart's valves and chambers so the pumping action of the heart can be studied. Echo is often combined with Doppler ultrasound and color Doppler to evaluate blood flow across the heart's valves. 
• Ejection fraction (EF). The EF test determines how well your heart pumps with each beat. This test measures how much blood is pumped out of the heart with each beat, and how much blood pumps through the heart with each beat. A normal EF is generally greater than 50%, which means that over half of the blood volume is pumped out of the heart with each beat. An EF of less than 40% usually confirms a diagnosis of systolic heart failure. An EF greater than 40% means that your heart failure is due to another cause, such as a valve disorder or diastolic dysfunction. Please note, however, that people with diastolic dysfunction can have a normal EF.
• Electrocardiogram (EKG or ECG). EKG records the electrical impulses traveling through the heart. During the test, small, flat, sticky patches called electrodes are placed on your chest. The electrodes are attached to an electrocardiograph monitor (EKG) that charts your heart's electrical activity on graph paper.
• Cardiac catheterization. This is one of the best tests for determining heart function and whether you have clogged heart arteries (coronary artery disease).
• Stress test. The patient’s heart is “stressed” by walking on a treadmill or by giving medications to increase pumping of the heart. It helps determine if someone may have clogged heart arteries.

Reviewed by the doctors at the Cleveland Clinic Heart & Vascular Institute.