Acute heart failure is sudden weakening of the heart pumping function, which leads to accumulation of liquids in the lungs. It most often occurs after a heart attack, affecting the left side predominantly.

In acute heart failure, the liquids accumulate in the blood vessels leading from the lungs to the heart and when there is stronger pressure, the liquids leak into the lungs, which is pulmonary edema, life-threatening condition unless treated.

Medical term for measuring the pumping function of the heart is ejection fraction. 50% or higher ejection fraction in a healthy heart means that 50% of the blood in the ventricle is pumped out with each heart beat.



The cause of acute heart failure occurs mostly in patients suffering from chronic heart failure, when the weakened heart is at strain. For instance, pneumonia may require harder work of the heart, which in turn can cause acute heart failure.

Other common causes are:

  • severe myocardial infarction
  • heart valve problems
  • infectious endocarditis
  • arrhythmia
  • complete heart block
  • tachycardia
  • stiff heart, for e.g. from high blood pressure
  • lower ejection fraction than 50

Right heart acute heart insufficiency is rare, but can occur when a blood clot blocks the pulmonary artery, coming out of the right heart.



The symptoms of acute heart failure develop suddenly, and these are:

  • significant shortness of breath
  • hissing sound of the lungs
  • cough with pink, foamy mucus
  • paleness and heavy sweat

When myocardial infarction is the cause, other symptoms may be: intensive, lasting chest pain and anxiety.

If pulmonary embolism is the cause, the symptoms may be coughing blood or severe chest pain, becoming worse while breathing in.

Unless treated, acute heart failure may cause fatal drop of the blood pressure.


Risk Factors

There are several risk factor for acute heart failure:

  • coronary artery disease
  • heart attack
  • valvular or congenital heart diseases
  • high blood pressure
  • arrhythmia
  • diabetes
  • viruses
  • obesity
  • smoking
  • alcohol use



Prevention of acute heart failure implies prevention of the risk factors, like control of high blood pressure, or other existing conditions, and the necessary lifestyle changes (healthy food, less salt, physical activity, no smoking and alcohol, and stress management).