Diagnosis

To diagnose heart failure, your doctor will take a careful medical history, review your symptoms and perform a physical examination. Your doctor will also check to see if you have risk factors for heart failure, such as high blood pressure, coronary artery disease or diabetes.

Your doctor can listen to your lungs for signs of fluid buildup (lung congestion) and your heart for whooshing sounds (murmurs) that may suggest heart failure. The doctor may examine the veins in your neck and check for fluid buildup in your abdomen and legs.

After the physical exam, your doctor may also order some of these tests:

• Blood tests. Blood tests are done to look for signs of diseases that can affect the heart.
• Chest X-ray. X-ray images can show the condition of the lungs and heart.
• Electrocardiogram (ECG). This quick and painless test records the electrical signals in the heart. It can show the timing and length of the heartbeats.
• Echocardiogram. Sound waves are used to produce images of the heart in motion. This test shows the size and structure of the heart and heart valves and blood flow through the heart. An echocardiogram can be used to measure ejection fraction, which shows how well the heart is pumping and helps classify heart failure and guides treatment.

• Stress test. Stress tests measure the health of the heart during activity. You may be asked to walk on a treadmill while attached to an ECG machine, or you may receive an IV drug that stimulates the effect of exercise on the heart.

  Sometimes a stress test is done while wearing a mask that measures how well the heart and lungs get oxygen and breathe out carbon dioxide.

• Cardiac computerized tomography (CT) scan. In a cardiac CT scan, you lie on a table inside a doughnut-shaped machine. An X-ray tube inside the machine rotates around your body and collects images of the heart and chest. Sometimes, contrast is given. Because the contrast agent could affect kidney function, talk to your doctor if you have kidney problems.

• Magnetic resonance imaging (MRI). In a cardiac MRI, you lie on a table inside a long, tubelike machine. Radio waves create images of the heart.

  A cardiac MRI may be done with a dye (contrast). It's important to tell your doctor about any problems with your kidneys before you receive a cardiac MRI or other MRI because contrast can cause a rare and serious complication in people who have kidney disease.

• Coronary angiogram. In this test, a thin, flexible tube (catheter) is inserted into a blood vessel, usually in the groin, and guided to the heart arteries. A dye (contrast) is injected through the catheter to make the arteries show up more clearly on an X-ray, helping the doctor spot blockages.
• Myocardial biopsy. In this test, a doctor inserts a small, flexible cord into a vein in the neck or groin, and removes very small pieces of the heart muscle for examination. This test may be done to diagnose certain types of heart muscle diseases that cause heart failure.

Results of tests to diagnose heart failure help doctors determine the cause of any signs and symptoms and decide on a treatment plan. To determine the best treatment for heart failure, doctors may classify heart failure using two systems:

New York Heart Association classification

This scale groups heart failure into four categories.

• Class I heart failure. There are no heart failure symptoms.
• Class II heart failure. Everyday activities can be done without difficulty but exertion causes shortness of breath or fatigue.
• Class III heart failure. It's difficult to complete everyday activities.
• Class IV heart failure. Shortness of breath occurs even at rest. This category includes the most severe heart failure.

American College of Cardiology/American Heart Association classification

This stage-based classification system uses letters A to D and includes a category for people who are at risk of developing heart failure. Doctors use this classification system to identify risk factors and begin early, more aggressive treatment to help prevent or delay heart failure.

• Stage A. There are several risk factors for heart failure but no signs or symptoms.
• Stage B. There is heart disease but no signs or symptoms of heart failure.
• Stage C. There is heart disease and signs or symptoms of heart failure.
• Stage D. Advanced heart failure requires specialized treatments.

Your doctor often will use both classification systems together to help decide the most appropriate treatment options. Your doctor can help you interpret your score and plan your treatment based on your condition.