How Heart Failure Is Diagnosed

In This Article

Symptoms of heart failure (shortness of breath, swelling) can mimic those of other health issues. It's important to bring such concerns to your doctor's attention, but she will use more than that to confirm that heart failure is the cause. 

The traditional diagnosis method for heart failure is based on heart function tests, which are primarily electrocardiogram (EKG) and echocardiogram (echo).

Brain natriuretic peptide (BNP) measurement has gained attention because it can be done using a blood test. It can be used with and EKG and an echo to piece together a diagnosis of heart failure.

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Recognizing the signs and symptoms of heart failure can help you get tested and receive the medical attention you need early in the course of the illness before your condition worsens. These can be subtle at first and may progress slowly, so it is easy to ignore them or simply chalk them up to aging. Knowing this, be sure to bring any of these concerns to your doctor's attention:

  • Shortness of breath: This can occur with mild to moderate exertion, when walking, lying down, bending over, or sleeping. You may repeatedly become short of breath, even when you are not exercising.
  • Fatigue: You may become easily tired, even when you haven't done anything that should be exhausting.
  • Edema: You may experience swelling or a puffy appearance of your feet or hands; usually, it's not painful or uncomfortable. If you apply pressure to the area and it becomes indented, remaining so for a few seconds or minutes (called pitting), it may indeed be a result of heart failure, rather than weight gain or unrelated fluid retention.

Labs and Tests

If you have the signs and symptoms of heart failure, and your doctor suspects the condition, she may run some tests to confirm a diagnosis.

Heart and lung auscultation: Your doctor will listen to your heart and lungs using a stethoscope on any routine medical visit. Normally, you should have a pattern of two heart sounds with every heartbeat. Heart failure often causes a third heart sound. Your lungs may sound congested on your lung examination if you have heart failure.

EKG: The most common test used to assess heart function, an EKG is a non-invasive test that involves placing electrodes on the surface of the chest to measure the electrical activity of the heart. If you have any symptoms of heart disease, your doctor is highly likely to order an EKG for you. A visual representation (or tracing) of that activity is produced on a piece of paper or on a computer. Abnormal patterns on EKG, including the presence of Q waves, left bundle branch block, ST depression, left ventricular hypertrophy, and arrhythmias are seen in heart failure.

B-type natriuretic peptide (BNP) test: This is the most common blood test used for heart failure. BNP, a protein hormone, is released into the blood circulation by heart muscle cells whenever the organ's internal pressure becomes too high. BNP causes the kidneys to excrete salt and water and reduces blood pressure to bring things back to normal.

In healthy people, BNP levels are usually below 125 pg/ml, and levels above 450 pg/ml are associated with heart failure. BNP levels between 100 pg/ml and 400 pg/ml are difficult to interpret, which is why this test is not considered diagnostic of heart failure, just supportive of it. It is a reliable test, but sometimes the interpretation may be in a gray zone.

Heart Failure Doctor Discussion Guide

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Imaging tests can be helpful in visualizing anatomical and functional changes in the heart, as well as some changes in the lungs, which can differentiate heart failure from other cardiac and pulmonary problems. Several options may be considered.

X-ray: A chest X-ray is a relatively quick imaging test that is often very helpful in diagnosing heart disease. Your chest X-ray may show that your heart appears enlarged or may show signs of congestion in your lungs if you have heart failure. If your doctor is concerned about lung or heart problems, it is likely that you will have a chest X-ray.

Echocardiogram: An echocardiogram, often referred to as an echo, is a non-invasive ultrasound test that visualizes the heart while it is in action. A small probe is placed on your chest, which a technician will move to capture the action of your heart valves and chambers as your heart naturally cycles. Your echo can provide a great deal of information about your heart function. In the setting of heart failure specifically, the thickness of your heart muscle, the filling and emptying of each chamber, and the heart rhythm are expected to be abnormal. Your doctor may order an echocardiogram for you if you have a heart rhythm abnormality or a possible heart muscle abnormality. 

Nuclear imaging: These imaging tests, including positron emission test (PET) and single photon emission computerized tomography (SPECT), involve the injection of radioactive dyes. The heart will either take up or not take up these radioactive particles dependng on how the heart muscle is functioning. These color changes can help your doctor detect if certain muscles of your heart are not able to pump as they normally would. PET and SPECT are both used to assist in the diagnosis of heart conditions, including CAD and heart failure.

Stress test: A stress test uses controlled exercise to uncover cardiac problems that may be brought out by exertion. It is particularly useful in evaluating angina (chest pain) caused by coronary artery disease. Your doctor may consider a stress test if you have symptoms that are worse with exertion. Often, people with advanced heart failure cannot tolerate a stress test, but it may also identify early heart failure.

Differential Diagnosis

If you have symptoms of heart failure, your medical team may consider other conditions that also cause shortness of breath or swelling of the extremities. Most of the time, there are diagnostic tests that can differentiate between these conditions and heart failure. However, the diagnosis can become more complicated if you have heart failure as well as another medical condition.

Chronic obstructive pulmonary disease (COPD): This condition causes shortness of breath, which is worse with exertion. COPD also causes wheezing and a cough that usually is associated with mucus. While some of the symptoms are similar to those of heart failure, COPD can be distinguished from heart failure by characteristic abnormalities on pulmonary function tests. COPD generally is caused by smoking and requires treatment with oxygen in late stages.

Pulmonary embolus (PE): A PE, a blood clot in one of the blood vessels of the lungs, causes breathing difficulties and chest pain. The characteristics of the dyspnea and chest pain people experience often differ between a PE and heart failure and can provide clues as to the cause of the symptoms. However, diagnostic testing is usually required to make the correct diagnosis.

Kidney failure: Kidney failure, like heart failure, can take time to develop, causing progressively worsening symptoms. When kidneys do not function as they should, fatigue and edema of the legs and arms can develop, as in heart failure. In general, kidney failure causes a change in electrolyte levels in the blood, which is not seen in heart failure.

Deep vein thrombosis (DVT): A DVT is a blood clot that often causes edema and may eventually cause a PE. A big difference between the edema of DVT and that of heart failure is that in DVT, the edema usually involves only one leg and it is not typically pitting. A DVT may cause a weak pulse in the affected limb, can be diagnosed with an ultrasound of the leg, and may be treated with blood thinners, depending on the location within the leg.

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Article Sources
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  1. Warning Signs of Heart Failure. American Heart Association. May 31, 2017.

  2. Minami Y, Kajimoto K, Sato N, et al. Third heart sound in hospitalised patients with acute heart failure: insights from the ATTEND study. Int J Clin Pract. 2015;69(8):820-8. doi:10.1111/ijcp.12603

  3. Taylor C, Hobbs R. Diagnosing Heart Failure – Experience and ‘Best Pathways.’ European Cardiology Review. 2010;6(3):10. doi:10.15420/ecr.2010.6.3.10

  4. NT-proB-type Natriuretic Peptide (BNP). Cleveland Clinic. Apr 25, 2019.

  5. COPD. National Heart Lung and Blood Institute.

Additional Reading
  • Fu S, Ping P, Wang F, Luo L. Synthesis, secretion, function, metabolism and application of natriuretic peptides in heart failure. J Biol Eng. 2018 Jan 12;12:2. doi: 10.1186/s13036-017-0093-0. eCollection 2018.

  • Hunter BR, Martindale J, Abdel-Hafez O, Pang PS. Approach to Acute Heart Failure in the Emergency Department. Prog Cardiovasc Dis. 2017 Sep - Oct;60(2):178-186. doi: 10.1016/j.pcad.2017.08.008. Epub 2017 Sep 1.

  • Lishmanov Y, Minin S, Efimova I, et al. The possible role of nuclear imaging in assessment of the cardiac resynchronization therapy effectiveness in patients with moderate heart failure. Ann Nucl Med. 2013 May;27(4):378-85. doi: 10.1007/s12149-013-0696-6. Epub 2013 Mar 1.

  • Minami Y, Kajimoto K, Sato N. Third heart sound in hospitalised patients with acute heart failure: insights from the ATTEND study. Int J Clin Pract. 2015 Aug;69(8):820-8. doi: 10.1111/ijcp.12603. Epub 2014 Dec 18.