Heart failure is a condition in which the heart fails to function properly. The terms "heart failure" and "congestive heart failure (CHF)" don't mean that the heart has actually "failed" or stopped but mean one or more chambers of the heart "fail" to keep up with the volume of blood flowing through them.
Heart failure is brought on by a variety of underlying diseases and health problems.
Your condition may involve the left side, the right side or both sides of the heart. Each side has two chambers:
Any one of these four chambers may not be able to keep up with the volume of blood flowing through it.
Two types of heart dysfunction can lead to heart failure, including:
The left side of the heart is crucial for normal heart function and is usually where heart failure begins. The left atrium receives oxygen-rich blood from the lungs and pumps it into the left ventricle, the heart's largest and strongest pump, which is responsible for supplying blood to the body.
After it has circulated through the body, blood returns to the right atrium and then travels to the right ventricle, which pumps it into the lungs to be replenished with oxygen. When the right side loses pumping power, blood can back up in the veins attempting to return blood to the heart.
Right heart failure may occur alone but is usually a result of left-sided failure. When the left ventricle fails, fluid backs up in the lungs. In turn, pressure from excess fluid can damage the heart's right side as it works to pump blood into the lungs.
Heart failure usually is a chronic, or long-term, condition that gradually gets worse. By the time most people notice and see a doctor about their symptoms, the heart has been "failing," little by little, for a long time.
This is a good reason to have regular health checkups. During a routine physical examination, your doctor may detect signs of heart failure long before you experience symptoms. Heart failure rarely occurs suddenly except after a major heart attack, severe heart valve problem or period of seriously high blood pressure.
People who experience any of the symptoms associated with heart failure, even if they are mild, should consult a doctor as soon as possible. Once a person is diagnosed, it's important to keep track of symptoms and report any sudden changes.
Typical signs of heart failure include:
Breathlessness or Shortness of Breath (Dyspnea) — When the heart begins to fail, blood backs up in the veins attempting to carry oxygenated blood from the lungs to the heart. As fluid pools in the lungs, it interferes with normal breathing. In turn, you may experience breathlessness during exercise or other activities. As the condition worsens, shortness of breath may occur when at rest or asleep. These periods of breathlessness may leave you feeling exhausted and anxious.
Fatigue — As heart failure becomes more severe, the heart is unable to pump the amount of blood required to meet all of the body's needs. To compensate, blood is diverted away from less-crucial areas, including the arms and legs, to supply the heart and brain. As a result, people with heart failure often feel weak (especially in their arms and legs), tired and have difficulty performing ordinary activities such as walking, climbing stairs or carrying groceries.
Chronic Cough or Wheezing — The fluid buildup in the lungs may result in a persistent cough or wheezing, that may produce phlegm (a thick, mucous-like substance) that may be tinged with blood.
Rapid or Irregular Heartbeat — The heart may speed up to compensate for its failing ability to adequately pump blood throughout the body. Patients may feel a fluttering in the heart (palpitations) or a heartbeat that seems irregular or out of rhythm. This often is described as a pounding or racing sensation in the chest.
Lack of Appetite or Nausea — When the liver and digestive system become congested they fail to receive a normal supply of blood. This can make you feel nauseous or full, even if you haven't eaten.
Mental Confusion or Impaired Thinking — Abnormal levels of certain substances, such as sodium, in the blood and reduced blood flow to the brain can cause memory loss or disorientation, which you may or may not be aware of.
Fluid Buildup and Swelling — Because blood flow to the kidneys is restricted, the kidneys produce hormones that lead to salt and water retention. This causes swelling, also called edema, that occurs most often in the feet, ankles and legs.
Rapid Weight Gain — The fluid build-up throughout the body, may cause you to gain weight quickly.
These symptoms occur as the heart loses strength and the ability to pumped blood throughout the body. In turn, blood can back up and cause "congestion" in other body tissues, which is why heart failure sometimes is called "congestive." In addition, excess fluid may pool in the failing portion of the heart and the lungs.
At the same time, the heart as well as other parts of the body attempt to adapt and make up for the deteriorating pumping ability. For example:
Heart Grows Larger — The muscle mass of the heart grows in an attempt to increase its pumping power, which works for a while. The heart chambers also enlarge and stretch so they can hold a larger volume of blood. As the heart expands, the cells controlling its contractions also grow.
Heart Pumps Faster — In an attempt to circulate more blood throughout the body, the heart speeds up.
Blood Vessels Narrow — As less blood flows through the arteries and veins, blood pressure can drop to dangerously low levels. To compensate, the blood vessels become narrower, which keeps blood pressure higher, even as the heart loses power.
Blood Flow Is Diverted — When the blood supply is no longer able to meet all of the body's needs, it is diverted away from less-crucial areas, such as the arms and legs, and given to the organs that are most important for survival, including the heart and brain. In turn, physical activity becomes more difficult as heart failure progresses.
Although the body's ability to compensate for the failing heart initially is beneficial, in the long run these adaptations contribute to the most serious cases of heart failure. For example:
An enlarged heart eventually doesn't function as well as a normal heart, and the extra muscle mass adds stress to the entire cardiovascular system.
The organ systems from which blood has been diverted may eventually deteriorate because of an inadequate supply of oxygen.
Narrowing of the blood vessels limits the blood supply and can contribute to conditions such as stroke, heart disease and clogged or blocked blood vessels in the legs and other parts of the body.
Pumping blood too fast for too long can damage the heart muscle and interfere with its normal electrical signals, which can result in a dangerous heart rhythm disorder.
Eventually, the heart and body are unable to keep up with the added stress. If patients wait until they experience obvious symptoms of heart failure before seeing a doctor, the condition already may be life-threatening. If you experience any of these symptoms, consult your doctor as soon as possible.
Reviewed by health care specialists at UCSF Medical Center.
Advanced Heart Failure Evaluation and Therapies Program
400 Parnassus Ave., Sixth Floor, Suite A-6110
San Francisco, CA 94143-0118
Phone: (415) 353-4145
Fax: (415) 353-4166