Heart failure develops when the heart doesn’t function properly. Heart failure doesn’t mean that the heart has failed or stopped. People often live healthy lives by controlling this condition, which refers to one or more chambers of the heart “failing” to keep up with the volume of blood flowing through them.
Heart failure may involve the left side, the right side or both sides of the heart. Each side has two chambers — an atrium (upper chamber) and a ventricle (lower chamber). Heart failure occurs when any one of these four chambers is no longer able to keep up with the volume of blood flowing through it.
Two types of heart dysfunction can lead to heart failure, including:
- Systolic Heart Failure — This is the most common cause of heart failure and occurs when the heart is weak and enlarged. The muscle of the left ventricle loses some of its ability to contract or shorten. In turn, it may not have the muscle power to pump the amount of oxygenated and nutrient-filled blood the body needs.
- Diastolic Failure — The muscle becomes stiff and loses some of its ability to relax. As a result, the affected chamber has trouble filling with blood during the rest period that occurs between each heartbeat. Often the walls of the heart thicken, and the size of the left chamber may be normal or reduced.
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.
Although the death rate from coronary artery disease and other heart conditions has been declining, the number of deaths from heart failure — also called congestive heart failure — is rising and is expected to balloon as the population ages.
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. Heart failure can be brought on by a variety of underlying diseases and health problems.
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)
- Fatigue
- Chronic cough or wheezing
- Rapid or irregular heartbeat
- Lack of appetite or nausea
- Mental confusion or impaired thinking
- Fluid buildup and swelling
- Rapid weight gain
These symptoms occur as the heart loses strength and the ability to pump 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 — The heart speeds up in an attempt to circulate more blood throughout the body.
- 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.
Treatment focuses on improving the symptoms and preventing the progression of the disease. Treatments include lifestyle and pharmacological modalities. Reversible causes of the heart failure should also be addressed:
- Infection
- Alcohol ingestion
- Anemia
- Thyrotoxicosis
- Arrhythmia
- Hypertension