How Is Heart Failure Diagnosed?

Your doctor will diagnose heart failure based on your medical and family histories, a physical exam, and tests. Because the symptoms of heart failure also are common in other conditions, your doctor must:

• Find out whether you have a disease or condition that can cause heart failure, such as coronary artery disease (CAD), high blood pressure, or diabetes
• Rule out other causes of your symptoms
• Find any damage to your heart and measure how well your heart pumps blood

Early diagnosis and treatment can help people with heart failure live longer, more active lives.

Medical and Family Histories

Your doctor will ask whether you or others in your family have or have had a disease or condition that can cause heart failure.

Your doctor also will ask about your symptoms. He or she will want to know which symptoms you've have, when they occur, how long you've had them, and how severe they are. The answers will help show whether and how much your symptoms limit your daily routine.

Physical Exam

During the physical exam, your doctor will:

• Listen to your heart for sounds that aren't normal
• Listen to your lungs for the sounds of extra fluid buildup
• Look for swelling in your ankles, feet, legs, abdomen, and the veins in your neck

Diagnostic Tests

No one test shows whether you have heart failure. If you have signs and symptoms of heart failure, your doctor may order an EKG (electrocardiogram), a chest x ray, and a BNP blood test as initial tests.

Initial Tests

EKG. This simple test shows how fast your heart is beating and whether its rhythm is steady or irregular. An EKG may show whether you have had a heart attack or whether the walls in your heart's pumping chambers are thicker than normal. Thicker walls can make it harder for your heart to pump blood.

Chest x ray. A chest x ray takes a picture of your heart and lungs. It can show whether your heart is enlarged, whether you have fluid in your lungs, or whether you have lung disease.

BNP blood test. This new test checks the level of a hormone called BNP, which rises during heart failure.

Followup Tests

Your doctor may refer you to a cardiologist if your initial test results indicate heart failure. A cardiologist is a doctor who specializes in treating people with heart problems.

The cardiologist will likely order one or more other tests to confirm the diagnosis.

Echocardiography. Echocardiography uses sound waves to create a moving picture of your heart. It shows the size and shape of your heart and how well parts of your heart are working. The test also can show where blood flows poorly to the heart, where the heart muscle doesn't contract as it should, and damage to the heart muscle caused by poor blood flow.

Sometimes this test is done both before and after your heart is put through physical stress (see stress testing below). Testing under stress helps show whether there's a lack of blood flow to your heart (a sign of CAD).

Doppler imaging. A Doppler test uses sound waves to measure the speed and direction of blood flow. It's often done with an echocardiogram to give a more complete picture of blood flow to the heart and lungs.

Doppler is often used to find out whether you have right-side heart failure (this is when the heart can't fill with enough blood).

Holter monitor. A Holter monitor is a small box that you carry in a pouch around your neck or clipped to your belt. It's attached to sticky patches called electrodes that are placed on your chest. The device records your heart rhythm for a full 24- or 48-hour period, while you do your normal daily activities.

Nuclear heart scan. A nuclear heart scan is a test that shows how well blood is passing through your heart and how much blood is reaching your heart muscle.

Your doctor will inject a radioactive substance into your bloodstream, which will make your heart chambers and vessels easy to see. Then, a special camera is used to show where the substance lights up (in healthy heart muscle) and where it doesn't (in damaged heart muscle).

Your doctor may want to do this test while your heart is under physical stress (see stress testing below).

Cardiac catheterization. During cardiac catheterization (KATH-e-ter-i-ZA-shun), a long, thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck and threaded to your heart. This allows your doctor to study the insides of your coronary arteries. Coronary arteries carry oxygen-rich blood to your heart.

During this procedure, your doctor can check the pressure and blood flow in the heart's chambers, collect blood samples, and use x rays to look at the coronary arteries.

Coronary angiography. Coronary angiography (an-jee-OG-ra-fee) is usually done with cardiac catheterization. A dye that can be seen on x ray is injected into the blood through the tip of the catheter. The dye allows your doctor to see the flow of blood to the heart muscle. This test also shows how well your heart is pumping.

Stress test. Some heart problems are easier to diagnose when your heart is working harder and beating faster than when it's at rest. During stress testing, you exercise (or are given medicine if you can't exercise) to make your heart work harder and beat faster. You may walk or run on a treadmill or pedal a bicycle.

Heart tests, such as nuclear heart scanning and echocardiography, are done during stress testing.

Cardiac magnetic resonance imaging (MRI). A cardiac MRI scan shows, in detail, the structures and beating of your heart. An MRI scan can help your doctor see whether parts of your heart are damaged. Doctors also are using MRI in research studies to find early signs of heart failure, even before symptoms appear.

Positron emission tomography (PET). PET scanning shows the level of chemical activity in areas of your heart. This scan can help your doctor see whether enough blood is flowing to these areas. It can show blood flow problems that other types of scans may not pick up.

Thyroid function tests. Thyroid function tests show how well the thyroid is working. They include blood tests, imaging tests, and tests to stimulate the thyroid. These common tests are key in checking for heart failure. Having too much or too little thyroid hormone in the blood can cause heart failure.