Diagnosing Heart Failure

First steps for getting diagnosed

It’s important to have regular checkups even if you’re not noticing any specific symptoms. If you do notice any potential signs of heart failure, talk to a health care professional.

Symptoms to report to your health care professional 

It can be appropriate to begin testing for heart failure if you or a family member has any of the signs of heart failure, such as:

• Shortness of breath
• Persistent coughing or wheezing
• Buildup of excess fluid in body tissues (edema)
• Unusual fatigue
• Lack of appetite or nausea
• Impaired thinking
• Increased heart rate 

Testing can provide insights 

After an exam, your health care professional may decide that tests and procedures are needed to understand what’s happening. Imaging tests can help show the structure and function of your heart’s chambers and ventricles. Blood tests can show how much oxygen and electrolytes are circulating. This information can help clarify what is responsible for your heart failure symptoms.

Interpreting the results 

Your health care professional uses your test results to determine whether you have heart failure, as well as:

• The type of heart failure 
• The class of heart failure
• The degree of severity

Testing can also suggest which HF treatments would be most effective.

Common Tests for Heart Failure 

Your health care team might perform some or all of these diagnostic tests and procedures. Before having any kind of test or exam, tell your health care professional about:

• Health problems
• Recent surgeries 
• Allergies 
• Whether you are pregnant

Different facilities and exams have varying guidelines about eating and drinking before the test. Eat food, drink fluids and take your medications as usual unless you are told otherwise. 

Physical examination

What to expect:

• You will be asked about your medical history, list of medications and symptoms. You may fill out forms with this information before your exam. Your health care professional could ask you the questions again during the exam.
• You will have your blood pressure taken and be weighed.
• Your health care professional will listen to your heart and lungs using a stethoscope. They will also look for any swelling in your feet, ankles and abdomen and assess your cognitive state.

Tips for success:

• Your health care professional can’t make a correct diagnosis without your full input. Think of your health care team as your partners. You have to work together to succeed.
• Don’t be afraid to “look bad.” For instance, if you smoke, eat high-fat foods or are physically inactive, be honest. That information helps determine your risk for heart failure.
• Follow all instructions to prepare for your exam. You could be told not to eat or drink for a certain amount of time before your appointment.
• Take all your medications or a list of all your medications to your appointment. This includes over-the-counter drugs, vitamins and supplements as well as prescriptions. 

Blood tests

How blood tests are performed:

• A health care professional will draw a blood sample from your arm. 
• They will send the sample to a lab to analyze biomarkers that help to diagnose and manage heart failure. These include:
  
  • Natriuretic peptides, including B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP), markers for diagnosing heart failure and disease severity 
  • Electrolytes (sodium, potassium) 
  • Albumin (a marker of nutritional and liver function)
  • Creatinine (to assess kidney function)

What blood tests show: Abnormal results could show a strain on the heart or other organs, such as the kidneys and liver, which often results from heart failure. 

Chest X-rays

Chest X-rays are painless. They could be taken in the health care professional’s office or in a radiology lab. Further imaging tests will likely be needed after a chest X-ray. These images are a first step in diagnosing heart failure. They cannot capture all the details needed for a diagnosis.

Here’s how chest X-rays are performed: 

• Wear loose-fitting clothing to be more comfortable. You could be asked to wear a gown.
• Before the X-rays are taken, remove any metal:
  • Jewelry
  • Removable dental appliances
  • Glasses
• If you have any medical devices or if you might be pregnant, tell your health care professional before the X-ray testing begins.
• X-rays are taken while you stand up or lie down on a table. Your technician will cover parts of your body to protect them from the radiation used to take images.
• A technician will use the X-ray machine to take pictures of your heart.
• X-ray images can be taken from the back, front and the sides to get a full view of your heart from every angle.

What X-rays show:

• Whether the heart is enlarged
• Whether there is congestion in the lungs
• Whether something other than heart failure is causing your symptoms

Learn more about chest X-rays.

Electrocardiogram (EKG)

Electrocardiograms are painless. They capture your heart’s electrical activity. Here’s how an EKG is performed:

• You will lie still on a table while a health care professional places small electrodes (round plastic discs) on your chest.
• Wires run from the electrodes to the EKG machine, carrying recordings of:
  • Your heart’s rhythm
  • Frequency of beats 
  • Electrical conduction

An EKG reveals:

• Whether you’ve had a heart attack
• If the left ventricle is thickened (enlarged heart muscle wall)
• If the heart rhythm is abnormal (noting arrhythmias such as atrial fibrillation)
• The strength and timing of your heartbeat

Learn more about an electrocardiogram.

Echocardiography

An echocardiogram, also called an echo, uses sound waves to study the heart’s structure and motion. How echocardiography is performed: 

• You might need to be sedated (asleep), depending on what type of echo you are having. 
• You might be given a gown to wear.
• You will lie either on your back or left side on an exam table while a technician moves a device over your chest. 
• The technician’s device gives off a silent sound wave that bounces off your heart, creating images of the chambers and valves.

An echo reveals:

• How thick the heart muscle is
• How well the heart pumps
• The size and shape of your heart
• Your heart’s ejection fraction.
• The condition and function of your four heart valves (tricuspid, pulmonic, mitral, aortic)

Learn more about echocardiography.

Exercise stress test

An exercise stress test measures how well your heart works when your body is active. The test is painless but could feel strenuous. It takes about 15 minutes. How a stress test is performed: 

• You will be connected to a heart monitor. This will include:
  • EKG to measure electrical activity in your heart and your heart rate
  • Blood pressure monitor
• It might include an imaging test such as an echo, cardiac MRI or a nuclear heart scan.
• You might wear a mask or mouthpiece that measures how your body uses oxygen when active.
• You will walk slowly in place on a treadmill or pedal slowly on a stationary bike. Then your care team might increase the treadmill’s speed and angle to produce the effect of going up a small hill.
• Your care team will check your heart rate and rhythm, breathing and blood pressure, and how tired you feel during the test.
• Your care team will ask you to keep up the pace for as long as you can, but you can stop the test at any time, if needed. They will also stop the test if you show signs of a heart problem or are too tired to continue. 
• Afterward, you will sit or lie down while your care team checks your heart and blood pressure.

If you cannot exercise, you will be given medication to raise your heart rate to mimic how it would behave during exercise. They will deliver this medication through an IV line. This test takes about 10–20 minutes.

An exercise stress test reveals:

• How your heart responds to exercise
• Whether the blood supply is reduced in the arteries that supply your heart
• The kind and level of exercise that’s right for you
• Which treatment plan would likely work best for you

Learn more about exercise stress test.

Radionuclide ventriculography or multiple-gated acquisition scanning (MUGA)

MUGA scans take multiple pictures of your heart at different points in time to create a film of many cardiac cycles. The test is painless, except for a shot or an IV at the beginning. There’s no lasting effect from the radionuclides used.

This test is helpful for people at risk of heart failure because of chemotherapy treatment for cancer. Repeating the test allows your health care team to better understand your heart’s function before, during and after chemotherapy.

How the procedure is done:

• Radioactive substances called radionuclides are injected into the bloodstream. These substances will attach to your red blood cells, showing them as they move through your body.
• Computer-generated pictures display the locations of the radionuclides in the heart.

A MUGA scan reveals:

• An enhanced view of the structure and dynamics in your heart
• How well the heart muscle is supplied with blood
• How well the heart’s chambers are working
• Whether part of the heart has been damaged by a heart attack
• How your blood moves through your heart
• How well your heart functions at rest and while under stress

Learn more about a MUGA scan.

Cardiac catheterization

Cardiac catheterization evaluates blood flow through the coronary (heart) arteries.

How the procedure is done:

• Your care team will insert a small wire (catheter) into a blood vessel in your upper thigh or arm. The catheter may have a tiny camera on the end to help provide your health care professional with images of your heart. Your care team can use it to gather blood or heart muscle samples.
• Your care team will feed the tip of the wire from the entry point in your body to the heart or arteries.
• Your care team will inject a special fluid (a contrast medium or dye) that helps make your heart visible. An ultrasound might also be used to get more images during the procedure.
• The pictures taken during this procedure are called angiograms.
• This procedure could involve some discomfort from the placement of the catheter. You could be required to rest in a specific position after the procedure.

A cardiac catheterization reveals:

• Blockages in the coronary (heart) arteries
• If the parts of your heart fed by the blocked or narrowed arteries are weakened or damaged from a lack of blood
• The oxygen levels and blood pressure in your heart chambers and pulmonary arteries

Learn more about cardiac catheterization.

Cardiac magnetic resonance imaging (MRI)

Cardiac MRI creates detailed pictures of the structures within and around your heart using a powerful magnetic field, radio waves and a computer. The test is painless and uses no radiation. The magnetic field is not harmful. 

The test could disrupt some medical devices. Review your medical devices with your care team before having a cardiac MRI. If you have claustrophobia or anxiety, ask about options for taking a mild sedative.

How an MRI is performed:

• A radiologist or MRI technologist usually performs the scan in a hospital, clinic or imaging center.
• You will lie on a movable table that slides into the MRI machine. The machine looks like a long metal tube. Your care team might use straps and bolsters to help you lie still and stay as comfortable as possible. 
• Your technician will watch you from another room. You can talk with them by microphone. Sometimes, a friend or family member may stay in the room with you.
• Your care team might attach electrodes to your chest to help them synchronize the images they take with your heartbeats.
• The machine will create a strong magnetic field around you. Radio waves will be directed at the area of your body to be imaged. You won’t feel the magnetic field or radio waves.
• During the scan, the magnet produces loud tapping or thumping sounds and other noises. You might be given earplugs or headphones to listen to music to help block the noise. Your care team could also do multiple runs of the test. Some runs can last several minutes. Each one will create different noises.
• In some cases, such as for an MRA (magnetic resonance angiography), you might have an IV line in your hand or arm for injecting a contrast agent into your veins. The contrast agent produces detailed images of your tissues and blood vessels. 
• A cardiac MRI scan lasts between 30 and 90 minutes.

A cardiac MRI reveals:

• Your heart’s structure (muscle, valves and chambers) and how well blood flows through your heart and major vessels
• If your heart is damaged from a heart attack 
• If there is a lack of blood flow to the heart muscle due to narrowed or blocked arteries

Learn more about MRI.