What is heart failure?
Heart failure is not cardiac arrest. Heart failure is a chronic, long-term condition where the heart is unable to pump an adequate supply of blood throughout the body. Heart failure is sometimes referred to as congestive heart failure or CHF.
How does heart failure compare to a healthy heart?
When a healthy heart beats, blood constantly moves through it and is pumped out to the rest of the body. Oxygen-poor blood (blue arrows) enters from the body into the right side of the heart and is pumped out to the lungs. Oxygen-rich blood comes(red arrows) in from the lungs to the left side of the heart and is pumped to all other parts of the body.
In a heart with heart failure, one or more of the chambers of the heart is unable to pump correctly, meaning the blood is not moved through the body efficiently. This may cause the heart to attempt to compensate for its loss of function.
The heart may:
- Enlarge one or more chambers to force a stronger contraction
- Increase muscle mass to pump stronger
- Beat faster to compensate for a weakened beat
- Constrict the surrounding blood vessels to improve blood pressure
These measures may initially improve blood flow, but they will eventually become ineffective and further weaken the heart. As heart failure continues to decline, the body may divert blood away from tissue and organs to sustain blood flow to the brain and heart.
What causes heart failure?
Heart failure can be the result of a variety of cardiac problems including:
- Coronary artery disease: a narrowing of the arteries that prevents adequate blood from reaching the heart
- A past heart attack
- High blood pressure
- Congenital heart disease
- Lung disease
- Sleep apnea: episodes of blocked or stopped breathing during sleep
- Illness, certain birth defects, smoking, and drug and alcohol abuse can also cause heart failure because they can weaken the heart muscle
What is ejection fraction?
Ejection fraction (EF) measures how much blood the heart pumps out (ejects). This measure is helpful in diagnosing heart failure. A healthy heart pumps at least half of the blood from the ventricles (the two lower chambers of the heart) with each beat. This means a normal ejection fraction is around 50 percent or more.
Heart failure is often classified as either low ejection fraction or normal ejection fraction heart failure.
- Low ejection fraction heart failure means that your heart muscle cannot pump, or eject, the blood out of the heart very well
- Normal ejection fraction heart failure means that your heart’s pumping chamber is stiff and the pressure within the heart is too high
With these problems the heart is either no longer able to pump enough blood out to the rest of your body or the pressure within the heart is high so that fluid may build up in the body or lungs. As the heart’s pumping action is lost, blood may back up in other areas of the body, producing congestion in the lungs, the liver, the gastrointestinal tract and the arms and legs. As a result, there is a lack of oxygen and nutrition to organs, which damages them and reduces their ability to work properly.
What are the symptoms of heart failure?
Heart failure symptoms can range from mild to severe. Symptoms should be closely monitored to check for signs of worsening heart failure.
Symptoms of heart failure include:
- Shortness of breath, wheezing, or coughing
- Feeling weak or tired, even after little effort
- Problems breathing when you’re lying flat, or the need to sleep in a recliner or propped up on pillows
- Waking up at night coughing or short of breath
- Rapid weight gain of more than two pounds in a day or more than five pounds in a week
- Swelling in the hands, abdomen, ankles or feet
Mild heart failure may not have any initial symptoms. It is important to have regular checkups with your doctor to check for early signs of heart failure.
Can heart failure be prevented?
Some causes of heart failure such as birth defects, disease and age cannot be prevented. Living a healthy lifestyle, however, can greatly reduce your risks of developing heart failure and other types of heart disease.