Acute heart failure is a condition that means that the heart is not working properly. It occurs suddenly and can be life threatening.

If a person has heart failure, their heart is either not able to work effectively enough to supply blood to the body or not able to relax normally, which causes fluid to build up in the lungs.

As a result, the person may have breathlessness, changes in heart rhythm, and fluid retention, leading to swelling in the legs and elsewhere.

The symptoms of acute heart failure either appear suddenly or worsen quickly. However, the underlying cause is usually heart damage or heart stiffness. Sometimes, the stiffness could have been occurring over a long period of time.

Anyone with symptoms of heart failure needs immediate medical attention. A doctor may recommend taking medication, making certain lifestyle changes, or undergoing surgery.

This article looks at the causes, symptoms, and facts associated with acute heart failure to help people better understand this condition.

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Heart failure means that the heart is unable to pump enough blood or relax sufficiently to serve the body’s needs.

In some cases, acute heart failure results from a sudden event, such as a virus or a trauma or blockage affecting an artery around the heart. Some people call this de novo acute heart failure.

However, when it results from long-term underlying damage in the heart, it is called acute on chronic heart failure.

Some other ways of describing heart failure include:

Heart failure can affect one or both sides of the heart. However, it usually starts on the left side.

Left sided heart failure can be diastolic or systolic. Systolic heart failure affects the left ventricle and the way it pumps blood out. Diastolic heart failure happens when the left ventricle does not relax properly.

Right sided heart failure can happen alone but often occurs with left sided heart failure, when the left chamber puts pressure on the right side.

Congestive heart failure develops when blood flow from the heart becomes slower, causing a backup of blood returning to the heart. Fluid collects in the legs, abdomen, lungs, and other parts of the body. If it collects in the lungs, the person will have pulmonary edema.

The heart has four chambers, which work together to pump blood around the body. Problems can arise in any part of the heart.

In de novo acute heart failure, a single problem or event causes symptoms. This may be a virus, drug use, or sudden damage to a heart valve or a blockage in a coronary artery (blood vessel around the heart).

Sometimes, a person will have acute on chronic heart failure. This develops as the heart tries to compensate for a loss of function (squeezing or relaxing function) that has built up over time.

Here are some of the measures that the heart takes to compensate:

  • The heart stretches so that it can contract more, eventually becoming enlarged.
  • The heart develops increased muscle mass, which can stiffen the heart muscle.
  • The heart beats faster as it tries to supply more blood.
  • Blood vessels narrow to maintain blood pressure.
  • The body diverts blood away from other organs toward the heart.

In time, these changes can affect the health of the heart and other organs, such as the kidneys. A problem with the kidneys can also worsen edema from heart failure, as the body is unable to get rid of salt and water effectively.

Risk factors and comorbidities

Various factors can either increase the risk of heart failure or occur alongside it, possibly with the same underlying cause.

Someone with acute heart failure may also have:

Some factors that can trigger acute heart failure include:

  • acute coronary syndrome
  • a stroke
  • a previous heart attack
  • physical trauma
  • the use of some drugs or a combination of medications
  • exposure to toxins
  • infections
  • discontinuing treatment for a heart condition
  • arrhythmia
  • high blood pressure
  • valvular heart disease

Studies suggest that 20–30% of people with acute heart failure also have kidney problems, and 40% have diabetes.

People with underlying heart problems may be more prone to experiencing lung infections and cellulitis. The heart’s inability to supply blood effectively can make it hard for the body to stay healthy overall.

Symptoms of acute heart failure include pulmonary edema and cardiogenic shock. These can lead to:

  • confusion
  • rapid breathing
  • a loss of consciousness
  • multiorgan failure

People with acute heart failure may have congestion and fluid retention, leading to:

  • breathlessness, especially with walking
  • swelling in the lower limbs or abdomen
  • shortness of breath when lying down
  • a need to sleep on extra pillows
  • weight gain
  • low blood pressure
  • progressive fatigue
  • a cough

To make a diagnosis, a doctor will carry out a physical examination and look at a person’s medical history.

Using a stethoscope, the doctor will listen to the person’s heart to check for unusual rhythms or extra heart sounds. They will also listen to the lungs to check for congestion.

The doctor may also check the abdomen, legs, and veins in the neck for swelling.

They may also recommend tests, such as:

  • an angiogram
  • imaging tests, such as a chest X-ray
  • blood tests
  • a chest CT scan, if there are signs of a pulmonary embolism or blood clot
  • echocardiogram

Many people with acute decompensated heart failure will need emergency medical treatment and will spend time in the hospital.

The treatment options will depend on the cause and how the person’s condition progresses. Below are some of the treatment options.

Oxygen therapy

A person who has difficulty breathing will receive oxygen therapy. This may be through a mask or using mechanical breathing equipment and intubation.


Some examples of medications that a doctor may prescribe for acute heart failure include:

  • diuretics, to remove excess fluid
  • vasodilators, to dilate blood vessels
  • inotropes, to help the heart squeeze harder to help get the fluid out of the lungs
  • antibiotics, if there is a bacterial infection
  • treatment for arrhythmias

Surgery and other treatment

Other treatments will depend on the underlying cause of the condition and the specific symptoms or complications a person experiences.

They may include:

  • surgery, such as to repair heart valves
  • monitoring fluid balance, kidney health, and other factors
  • assessing blood pressure, heart rate, and other cardiac measures
  • counseling
  • preparing a follow-up plan that includes sodium and fluid restriction

As part of a person’s rehabilitation plan, a doctor may recommend some lifestyle choices that can help boost heart health.

These may include:

  • losing weight, if appropriate
  • following a healthful diet that is low in salt, fat, and sugar and high in fresh fruits and vegetables
  • getting regular exercise
  • managing stress through exercise, meditation, and rest
  • avoiding or quitting smoking
  • following up with one’s healthcare team and taking all medications as the doctor recommends
  • limiting sodium intake to fewer than 1,500 milligrams per day
  • limiting fluid intake to under 2 liters per day

People should be sure to check with their doctor before making any changes.

Learn more about following a heart-healthy diet here.

When a person has acute heart failure, it does not mean that their heart has stopped working altogether. However, it can be life threatening without prompt medical attention.

According to one 2018 research article, receiving treatment during the first hour can prevent severe complications. Prehospital treatment can help save a person’s life and minimize hospitalization. For this reason, people need help as soon as symptoms appear.

The outlook for people with acute heart failure depends on various factors. These include their overall health, the cause of the problem, how severe it is, and how quickly they receive treatment.

Many people live a full and healthy life after experiencing heart failure, but it is essential to follow all medical advice to prevent future problems.

In acute heart failure, symptoms appear or worsen suddenly. It can result from a sudden event, but it often results from a long-term heart problem.

Signs and symptoms include congestion, fluid retention, breathlessness, and changes in heart rhythm.

Anyone who may be experiencing acute heart failure needs immediate medical attention. Receiving treatment within the first few hours can prevent complications and save lives.

Read this article in Spanish.