What tests are useful in diagnosing and monitoring heart failure?

You probably completed an initial round of evaluations to get to your heart failure diagnosis. These early tests revealed the nature and extent of your heart failure and the underlying cause of the heart damage, helping to guide your treatment plan.

Your provider will likely perform additional tests at regular intervals throughout your care to monitor your condition and your response to treatment.

Medical history. The path toward a diagnosis always starts with a detailed conversation between you and your provider about your medical background and symptoms. Even after diagnosis, your history remains the best tool for gauging the progression of heart failure and in determining your course of treatment.

Some questions you may be asked include:

  • Do you have symptoms such as fatigue, swelling in the legs or abdomen, shortness of breath when active, or attacks of breathlessness while lying down?
  • Do you ever have chest pain? If so, what brings it on, and what makes it better?
  • Have you had any changes in appetite or lost or gained weight?
  • Do you have a history of other medical problems?
  • What are your habits regarding behaviors such as smoking, diet, and exercise?
  • What kinds of medications do you take?

Physical examination. Your provider can learn a lot from a physical examination. During the physical exam, your provider will measure your height and weight, take your blood pressure and pulse, and will observe your breathing. He or she may also be able to determine if you have an enlarged left ventricle by pressing on your chest wall in the region over the heart. Your provider may also evaluate:

  • Heart sounds. Doctors can detect disrupted blood flow through the heart—a sign of heart disease or damage—by listening for abnormal heart sounds.
  • Lungs and neck. When the heart loses pumping power, fluid can accumulate in the lungs, the veins, and the rest of the body. Doctors check the veins of the neck for signs of volume overload. They also listen to the lungs for crackling noises that might indicate fluid congestion.
  • Legs and abdomen. Your doctor may check your legs and abdomen for fluid buildup.
  • Skin changes. When the blood supply is limited by low output from the heart, your skin can feel cool and take on a pale, bluish color.

Diagnostic tests

Depending on the findings from your physical examination and your history, your doctor may order any of a number of tests.

Routine lab tests. Simple blood tests can provide a wealth of information about suspected heart failure. Specific blood tests may be repeated regularly to monitor your response to treatment.

  • Electrolyte tests check for imbalances of minerals in the blood—such as sodium and potassium—that can accompany heart failure. Testing also provides baseline levels for designing and monitoring drug treatment.
  • Liver and kidney function tests look for chemicals in the blood that signal abnormalities in the liver or kidneys. Heart failure or drugs used to treat the condition may affect the function of these organs.

Brain-type natriuretic peptide (BNP) test. When blood backs up into the heart because it isn’t being pumped out efficiently, pressure rises. The heart cells register this change and sharply boost the secretion of a hormone called brain natriuretic peptide (BNP). BNP levels can help diagnose heart failure and gauge effectiveness of treatment. A related substance, N-terminal-pro-B-type natriuretic peptide (NT-pro-BNP), is also used in heart failure diagnosis.

Chest x-ray. Takes a picture of your heart. Signs of heart failure such as enlarged heart muscle or fluid buildup around the heart and in the lungs may show up on a chest x-ray.

Electrocardiography. An electrocardiogram (ECG) provides a picture of the electrical activity that regulates the heart’s cycle of contraction and relaxation. By evaluating an ECG, doctors can see whether your heartbeat is irregular, possibly find out whether your heart is enlarged, or detect signs of damage from an earlier heart attack.

Echocardiography. The most commonly used test for diagnosing heart failure is echocardiography (also called cardiac echo or just echo). It uses the echoes of sound waves to create a moving picture of your heart. The resulting video can reveal whether a person has systolic or diastolic heart failure. It also looks at your heart valves, how well your heart fills with blood and how well your heart pumps. This is called ejection fraction, the percentage or amount of blood pumped each your heart beats. Normal ejection fraction is between 55-70%. Patients with systolic heart failure often have a lower percentage.

Exercise testing. An exercise test shows how well your heart can meet the body’s needs when it has to work at maximum capacity. This is an important test for people with suspected heart failure, since sometimes the heart muscle can compensate well enough to mask signs of damage under normal circumstances but can’t pump hard enough to keep up with the demands of exertion.

Exercise testing may be used to measure your baseline exercise ability, gauge your response to treatment, or evaluate you as a candidate for medications and other treatments.

Coronary angiography (arteriography). Your provider will need to know if narrowing in the arteries leading to the heart is a likely cause of your heart failure. The gold standard for this diagnosis is coronary angiography (also called coronary arteriography).

In this procedure, the cardiologist inserts a thin tube called a catheter into a blood vessel and threads it through the circulatory system until it reaches the coronary arteries of the heart muscle. The physician then injects a contrast dye, which is visible on x-rays, into the coronary arteries. This allows the physician to see inside the blood vessels that feed the heart to identify any blockages that may exist.

Endomyocardial biopsy. In some cases, a sample of damaged heart muscle tissue is taken to identify the underlying cause of heart failure. Biopsy may be most useful in identifying a specific infection or heart muscle disease. It can also identify signs of rejection after a heart transplant.