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Acute Heart Failure

Written by Ada’s Medical Knowledge Team

Updated on

What is acute heart failure?

Heart failure is a state of reduced cardiac output, in which the heart cannot pump blood around the body effectively. When symptoms appear suddenly, or a person experiences rapid worsening of existing symptoms of heart failure, this is called acute heart failure (AHF) or acute decompensated heart failure (ADHF). This condition can be life threatening and should be urgently evaluated by a doctor, as outcomes can be affected by whether a person gets early and appropriate treatment. 1

Heart failure is a common condition which mostly affects people aged 65 or older. Heart failure is the most common cause of hospitalizations in the elderly, with around 1 million admissions per year in the United States. 2

Typical symptoms of acute heart failure include:

  • Shortness of breath
  • Tiredness
  • Swelling of the feet and legs

Treatment typically involves supporting breathing and adjusting the blood pressure and, where necessary, removing excess fluid from the body. There is no cure, but long-term treatment involving medications and rehabilitation can improve the heart’s function.

Acute heart failure vs chronic heart failure

Acute heart failure has a sudden onset and symptoms can appear without warning.

In chronic heart failure, that difficulty is ongoing and long-term. More people develop chronic heart failure than acute heart failure, and around 80 percent of acute heart failure cases are people with chronic heart failure whose symptoms rapidly become worse. 3 4

Read more about Chronic Heart Failure »

Symptoms of acute heart failure

Symptoms of acute heart failure can appear very quickly. It can be indicated by the appearance of new symptoms, or by an existing heart condition suddenly becoming worse.

General symptoms of acute heart failure include: 5 6 7

  • Shortness of breath while moving or lying flat, also known as dyspnea
  • Feeling tired
  • A cough that may be worse at night or when lying down
  • Swelling of feet, ankles, legs, abdomen or veins in the neck
  • Cool peripheries, such as hands and feet, due to reduced cardiac output
  • Veins in the neck protruding

Swelling, also known as edema, is caused by fluid building up in different parts of the body because the heart is no longer able to pump efficiently. This is known as congestive heart failure. Depending on the location in the body of the fluid buildup or congestion, this can cause other symptoms. For example: 7

  • Congestion in the kidneys can mean less urine being produced during the day, which leads to frequent urination during the night
  • Congestion in the bowel can lead to nausea and vomiting

Medical attention should be sought immediately if any symptoms of acute heart failure develop. Additionally, the free Ada app can be used to carry out a symptom assessment.

Less common symptoms of acute heart failure

Not everyone will experience the following symptoms of acute heart failure. Some of these symptoms are caused by an underlying condition. Less common symptoms of acute heart failure include:

  • Palpitations, the feeling that the heart has skipped or added a beat, where the person has arrhythmia
  • Fever, which can be caused by underlying infection
  • Fainting, also called syncope
  • Blue/colored lips, skin or tongue, also called central cyanosis

Complications of acute heart failure

Acute heart failure can cause other conditions, often as a consequence of fluid building up in different parts of the body.

Pulmonary edema

If fluid builds up in the lungs, this causes a very serious condition called pulmonary edema. Fluid is pushed into air sacs which reduces the lungs’ ability to transfer oxygen into the blood. This leads to shortness of breath, particularly when lying down. Other symptoms can include: 8 9

  • Coughing or, in some cases, coughing up blood
  • Wheezing
  • Sluggishness
  • Anxiety
  • Swelling in the legs or abdomen

Pulmonary edema can be life-threatening. Anyone showing signs of pulmonary edema should see a doctor immediately.


Acute heart failure can cause a buildup of fluid in the abdominal cavity. This is called ascites and can cause pain in the abdomen, bloating and shortness of breath. 10

Cardiorenal syndrome

Around one in four people who have acute heart failure also experience a significant worsening of kidney function, known as cardiorenal syndrome. The older a person is, the higher their risk of developing cardiorenal syndrome. The risk is increased if the person also has: 7 11

Cardiohepatic syndrome

Acute heart failure can lead to a worsening of liver function. Liver cells can be destroyed through pressure building up due to blood slowing down before entering the heart, which is a very serious condition. It can cause:

  • Jaundice, which is when skin and whites of eyes look yellow, urine becomes darker and stools become paler
  • Nausea
  • Vomiting
  • Abdominal pain

Another potential complication is cholestasis, where bile flow reduces or stops. This can cause jaundice, itchy skin, dark urine and bad smelling stools. 7 12 13 14

Causes of acute heart failure

The heart weakens with age, which particularly affects its ability to pump blood to the rest of the body. This makes people over the age of 65 more susceptible to factors that can cause AHF, such as a different heart condition or existing symptoms of heart failure.

There are various factors that can cause acute heart failure.

Other heart conditions can lead to acute heart failure, such as: 5 15 16 17 18 19

  • Cardiomyopathy, the general name for a range of diseases which cause the heart muscle to become enlarged, thick or stiff
  • Blood clots, which can lead to myocardial ischemia, which is where blood clots can partially or completely block the flow of blood to the heart, leading to coronary artery disease
  • Myocarditis, which is inflammation of the heart muscle
  • Endocarditis, which is a rare infection of inner lining of the heart and heart valves
  • Disease of the heart valves, or defects which can be present from birth
  • Arrhythmia in the lower chambers of the heart (ventricular arrhythmia) or in the upper chambers (supraventricular arrhythmia)

Hypertension is another cause of plaque buildup inside veins and can weaken the heart.

Other factors that can damage the heart and increase the risk of acute heart failure include: 3 5 20

Diagnosis of acute heart failure

Acute heart failure, as well as some of its complications such as pulmonary edema, is a very serious condition. Medical attention should be sought immediately if AHF is suspected.

Diagnosis is based on the symptoms, patient history and physical examination for signs that the heart is failing to pump enough blood.

Diagnostic tests can identify what type of heart failure is involved and which ventricle or side of the heart is involved, as treatments can differ. Tests that may be ordered include: 6 7 21 22

  • Electrocardiogram (ECG or EKG), which uses electrodes to monitor electrical activity in the heart
  • Blood oxygen levels should also be monitored
  • Various blood tests can show underlying causes for heart failure or reveal effects of complications
  • Chest X-ray, which can be useful to monitor response to treatment
  • Echocardiogram (an ECHO scan, or a heart ultrasound), which builds a picture of the heart as it pumps blood and can help identify the type of failure
  • MRI or computerised tomography (CT) scans can show damage to heart muscle
  • Nuclear ventriculography, which uses radioactive materials injected into the bloodstream to form an image of the heart moving

Types of heart failure which may occur in combination can be diagnosed by scanning, and testing the capabilities of the heart include: 5 23

  • Systolic failure: Also known as heart failure with reduced ejection fraction (HFrEF), this is when the left ventricle stops contracting normally and cannot circulate blood around the body properly.
  • Diastolic failure: Also known as heart failure with preserved ejection fraction (HFpEF), this is when the left ventricle stops relaxing properly and so cannot fill with enough blood during a heartbeat.

Treatment of acute heart failure

Acute heart failure can be life-threatening and anyone with symptoms should see a doctor as soon as possible. Treatment is initially focused on alleviating life-threatening symptoms, then on the investigation of underlying causes and treatment of residual symptoms. Hospitalization is generally required while cardiac performance improves. 4

There are a range of potential treatments for acute heart failure. The treatment that is applied will depend on the person’s symptoms and the underlying issue causing them. For example:

  • Shortness of breath (dyspnea): This symptom is treated with supplemental oxygen. The severity of dyspnea will dictate whether oxygen is supplied through a tube in the nose or a face mask. Sitting upright can help with breathing. 4 24
  • Buildup of fluid: Intravenous diuretics are used to treat buildup of fluid within the body. A pulmonary edema will also be treated with diuretics, as well as oxygen and heart failure medication. 9 25

Ongoing management of acute heart failure

Most patients with acute heart failure have worsening symptoms of chronic heart failure. As soon as the acute episode is stabilized, there are various types of medication which can be prescribed. Most of them are vasodilators, which widen the blood vessels to help lower blood pressure: 5 26 27 28 29 30

  • Angiotensin-converting enzyme (ACE) inhibitors, which lower blood pressure and reduce stress on the heart
  • Hydralazine, isosorbide and angiotensin receptor blockers (ARB), all of which work by relaxing blood vessels to lower blood pressure
  • Aldosterone antagonists, which reduce the body’s sodium levels to lower blood pressure
  • Beta blockers, which lower blood pressure and slow the heart rate
  • Digoxin, which makes the heart beat more strongly
  • Nitrates, which are usually given as a vasodilator when the person also has pulmonary edema
  • Painkillers, such as morphine, may be useful to reduce anxiety in people who are restless and distressed

Once the initial symptoms of acute heart failure have been brought under control, the condition needs to be managed to avoid further episodes. Drugs such as diuretics, ACE inhibitors and beta blockers are commonly prescribed. 6

People with severe heart failure may need cardiology surgery. This will often involve implanting a device to regulate the heartbeat, a cardiac pacemaker. 5

Anyone who has experienced acute heart failure should take steps to lead a healthy lifestyle, which will reduce pressure on the heart. This includes eating a healthy diet and taking exercise. (See Preventing acute heart failure.)

Preventing acute heart failure

Acute heart failure may be prevented by taking steps to maintain a healthy heart. This means following a healthy lifestyle: 31

Eating a healthy diet

This includes:

  • Fruits and vegetables
  • Whole grains, such as whole grain bread or brown rice
  • Reduced meat consumption
  • Low fat or fat-free dairy products
  • Beans, nuts and seeds
  • Limiting foods high in saturated and trans fats, such as full fat cheese and processed food
  • Avoiding foods that are high in salt/sodium or with added sugars

Good to know: Everyone who adapts their diet should consult their doctor to ensure that their food plan is right for them, as this differs between people, depending on any food sensitivities they may have and their general overall health.

Other lifestyle adaptations for preventing acute heart failure

  • Keep hydrated: Opt for water or non-alcoholic, non-caffeinated beverages with no added sugar. For people who wish to drink alcohol, it is recommended that men consume no more than two alcoholic drinks per day and women consume no more than one alcoholic drink per day.
  • Avoid using tobacco products: Doctors can provide advice on targeted services for those seeking to quit or cut down.
  • Avoid using illegal drugs
  • Get at least a moderate amount of exercise, such as two hours and 30 minutes of brisk walking per week
  • Maintain an appropriate weight, aiming for a body mass index (BMI) of 20-25
  • Manage stress levels, such as taking up meditation or exercise, or joining a therapy group

Hypertension, also known as high blood pressure, is a risk factor for developing acute and chronic heart failure. To learn more about how to prevent or manage high blood pressure, see the resource on Hypertension.

Diabetes and coronary heart disease, a condition where a substance called plaque builds up in the artery walls, are also risk factors for acute heart failure. People with these conditions should speak with their doctor about treatment options. 5

Chronic heart failure can lead to acute heart failure. People with chronic heart failure should learn how to recognize the early signs of worsening heart failure.

Other names for acute heart failure

  • Acute decompensated heart failure
  • Acute decompensation of heart failure

Acute heart failure FAQs

Q: Can acute heart failure be cured?
A: There are different underlying causes of acute heart failure. Most people who develop acute heart failure actually experience a worsening of existing chronic heart failure symptoms. In these cases, there is no definite cure. However, steps can be taken to manage symptoms and to prevent the condition becoming worse. See Preventing acute heart failure.