The doctor may suspect heart failure based on your medical history and symptoms, such as shortness of breath or edema. A complete physical exam will be done to look for other characteristic signs of heart failure, such as:

• Fluid in the lungs
• Enlargement of the jugular vein in the neck
• Enlargement of the liver
• High or low blood pressure
• Rapid heart rate—tachycardia
• Fluid accumulation in the abdominal cavity—ascites
• Fluid accumulation in the space between the lungs and ribs—pleural effusion

Your doctor may recommend tests to confirm the diagnosis and assess the degree of damage. Some tests can also eliminate other health conditions with symptoms similar to heart failure. Examples of these tests include:

• Blood tests—to look for other conditions, such as anemia, thyroid disorders, and high cholesterol. Blood tests evaluate the functioning of your kidneys and liver.
• Brain natriuretic peptide (BNP)—a hormone that is elevated in the blood when the heart is under strain. This is used as an indicator for heart failure.
• ECG—ECG records the electrical activity of your heart through 12 electrodes attached to the skin. This test will help diagnose heart rhythm problems, muscle abnormalities, and damage to the heart from a heart attack.
• Exercise stress test—This test records the heart's electrical activity during increased physical activity. It may be coupled with an echocardiogram or myocardial perfusion imaging. People who cannot exercise may be given IV medication that simulates the effects of physical exertion.

Imaging tests take pictures of the heart, blood vessels, and structures. Imaging tests for heart failure include:

• Chest x-ray—to see heart enlargement or congestion in the lungs
• Echocardiogram—ultrasound to evaluate the function of the heart's valves and chambers and to determine the amount of blood ejected from the heart with each heartbeat. An echocardiogram also can detect structural damage, tumors, or excess fluid around the heart.
• Myocardial perfusion imaging—Contrast material is used to observe the heart muscle. Areas with diminished blood flow can be detected on the scan.
• Coronary angiography and coronary catheterization—These tests help to detect obstruction in the arteries of the heart and assesses heart function. Testing to check for blockage in the coronary arteries is recommended for some individuals with heart failure, especially younger people and people with symptoms of chest pain and angina.
• CT angiography—Contrast material is used to detect areas with diminished blood flow.
• Electron-beam CT scan—creates images of the heart, lungs, and chest cavity
• Cardiac MRI—evaluates large blood vessels, coronary arteries, heart walls, and the pericardium, a double-walled sac that contains the heart

Stages and Classes of Heart Failure

Once the diagnosis is confirmed, your doctor will assess the stage and class of your heart failure.

Staging is based on heart damage and symptoms. The American Heart Association and American College of Cardiology Foundation stage heart failure as:

• Stage A—have high risk for heart failure without structural heart disease or heart failure symptoms
• Stage B—structural heart disease without heart failure signs or symptoms
• Stage C—structural heart disease with previous or current heart failure symptoms
• Stage D—heart failure that is not responding to standard treatment that needs specialized interventions

The New York Heart Association (NYHA) classifies heart failure based on symptoms and how they affect your abilities. NYHA classes are:

• Class I (mild)—no limitation of physical activity. Ordinary activity does not cause symptoms.
• Class II (mild)—slight limitation of physical activity. Ordinary activity causes heart failure symptoms, but resting does not.
• Class III (moderate)—marked limitation of physical activity. Less than ordinary activity causes heart failure symptoms, but resting does not.
• Class IV (severe)—unable to carry out any physical activity without heart failure symptoms, or symptoms are present while resting.