Heart failure means that your heart is unable to pump enough blood to your bodys tissues and organs to meet their needs.
The word 'congestive' refers to the fluid build-up that occurs as the failing heart pumps out less and less blood.
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Should your heart fail, you'll experience shortness of breath, fatigue and swelling of the feet, ankles and abdomen.
The mainstay of treatment is medication and lifestyle changes, but surgical procedures are becoming part of the therapeutic options.
Description
Heart failure occurs when your heart muscle doesn't contract strongly enough to pump enough blood to meet the bodys demands. "Failure" doesn't mean that the heart has stopped pumping, but that it does not pump effectively enough.
The heart is essentially a pump that circulates blood around the body. It pumps oxygenated blood to the body and deoxygenated blood to the lungs.
The heart has two main chambers: the right and left ventricle. Heart failure is most often caused by a poorly functioning left ventricle, the chamber that receives oxygen-rich blood from the lungs and pumps it out to the body.
Normally, the left ventricle pumps out more than half the blood it contains with each heartbeat (this volume is called the ejection fraction). When you have heart failure, the left ventricle pumps less blood than normal (30% to 40% or less).
As a result of the weakened pumping ability of the left ventricle (left-sided heart failure), a large portion of blood remains in the ventricle at the end of each contraction. This leaves little room for incoming blood from the lungs during the next heartbeat. Therefore, blood builds up inside the heart and lungs. This leads to symptoms of heart failure, such as shortness of breath.
With time, the right ventricle (which receives oxygen-poor blood from the body) pumps out less blood to the congested, blood-logged lungs, leading to a build-up of blood in the right ventricle. This in turn leaves less space for incoming blood from the body, causing blood to back up in the body (right-sided heart failure). This process results in swelling of the legs and abdomen.
When your heart doesn't pump normally, your hormonal and nervous systems try to make it pump more blood by increasing blood pressure, retaining sodium (salt) and water in the body, and increasing the heart rate. These responses are called compensatory responses, referring to the body's attempt to compensate for the poor blood circulation and back-up of blood and fluids. These compensatory steps may initially be of benefit, but eventually worsen the whole situation by contributing to congestion and reducing the percentage of blood pumped with each heartbeat (ejection fraction).
There are several different types of heart failure, depending on whether the left or right side of the heart is impaired, and whether the filling (diastolic) or pumping (systolic) function of the heart is not working properly. The most common form of heart failure is due to a problem with the pumping (systolic) ability of the left ventricle. This condition is called left ventricular systolic dysfunction.
Cause
Congestive heart failure is frequently the end result of many cardiovascular problems. Its most common causes include:
Ischaemic heart disease blockages of blood vessels in the heart with decreased oxygen supply to the heart muscle
Hypertensive heart disease damage to the heart muscle from longstanding high blood pressure
Cardiomyopathy a diseased heart muscle, often from an unknown cause
Valvular heart disease heart valve problems putting strain on the heart muscle
Arrhythmia-induced heart disease abnormal heart rhythm, leading to heart muscle damage
Congenital heart disease inborn abnormalities of the heart
Toxin-induced heart disease exposure of the heart to various toxins such as prolonged alcohol abuse
Constrictive pericarditis a disease of the sac surrounding the heart
Symptoms
At first, symptoms of heart failure may be absent although your internal pump is failing. Then gradually symptoms do occur because:
The body is not getting enough oxygen and nutrients.
Blood backs up into the lungs and body.
Compensatory responses occur, including tightening of the blood vessels and retaining of fluid in the body tissues, called oedema.
The earliest and most common symptoms of heart failure are lung or systemic congestion, which causes the following symptoms:
Shortness of breath while lying down that is relieved by sitting or standing up. A person may wake up coughing and/or wheezing, with a rapid heart rate, and the feeling of being suffocated. Difficult breathing and shortness of breath may occur during routine activities or exercise that did not previously cause breathing problems.
Dry, hacking cough, especially when lying down
Fluid build-up (oedema), especially in the legs, ankles, and feet
Dizziness, fainting, fatigue, or weakness
Rapid weight gain (due to fluid build-up)
Increased urination at night
Nausea, abdominal swelling, tenderness, or pain may result from fluid build-up in the abdomen
Swollen or distended neck veins
Prevalence
The good news death rates from stroke and heart attack are on the decline. The bad news the death rate from congestive heart failure is increasing. How can this increase in congestive heart failure be explained in the face of improving medical and surgical treatment?
Previously, if a person had heart disease, such as a valve abnormality, he or she would die at an earlier age, long before heart failure would develop. With better medical care and treatments available, heart disease is now identified and treated earlier, extending the lives of millions of people. However, people with heart disease who now live longer have increased chances of developing heart failure. Early diagnosis and treatment of heart failure is important to prevent complications, hospitalisation and early death.
Course
Chronic congestive heart failure is a life-long, progressive condition that may require many lifestyle changes and chronic medication. Adherence to the prescribed drug regimen can reduce the impact of heart failure on quality and length of life.
Symptoms of chronic heart failure may be minor and occur only during strenuous activity or exercise. Over time, symptoms worsen until they are present all the time, even during rest. Breathlessness, swelling, and fatigue will increase; however, treatment may help minimise these symptoms and the impact they have on your life.
Long-term complications of heart failure are generally due to:
Chronic fluid build-up, which may involve:
Lung congestion, ranging from mild to severe, with associated shortness of breath
Fluid build-up in the abdomen and liver, which can lead to liver problems or failure
Breakdown of skin (ulcers), especially in the legs, due to ongoing fluid build-up (oedema)
Cardiac arrhythmia (an abnormal heart rhythm) due to a disturbance in the electrical conducting system of the heart
Stroke, when the increased stasis of blood in the failing heart causes a blood clot in the heart, and this travels to the brain
Organ failure, such as kidney failure, due to decreased blood and oxygen supply to the body
Death related to the inability of the failing heart to provide the vital (life sustaining) organs with oxygenated blood
Risk factors
A range of cardiovascular problems may lead to congestive heart failure. If you suffer from any of these diseases, you are at risk of developing heart failure:
Ischaemic heart disease
Hypertensive heart disease
Cardiomyopathy
Valvular heart disease
Arrhythmia-induced heart disease
Congenital heart disease
Toxin-induced heart disease
Constrictive pericarditis
When to see a doctor
Seek care immediately for symptoms of sudden heart failure:
Severe shortness of breath (trouble breathing, even when resting)
A sudden episode of prolonged, irregular heartbeat with dizziness, nausea, or fainting
Foamy, pink mucus with coughing
A sense of impending doom related to the heart or lungs not functioning well
Call your doctor soon if you have symptoms of heart failure, which include:
Difficulty breathing during routine activities or exercise that did not previously cause problems
Shortness of breath when you lie down
Waking up at night short of breath or feeling as if you are suffocating
Dry, hacking cough, especially when you lie down
Rapid weight gain (1,3 to 1,8 kg or more in just a few days; unrelated to diet)
Skin sores developing as a result of fluid accumulation in the body (especially common in the legs)
Diagnosis
The health professional may do the following investigations:
History and physical examination
Laboratory tests
Electrocardiogram
Chest X-ray
Echocardiography
Radionucleotide ventriculogram
History and physical examination
In obtaining a medical history, the health professional will ask about the following:
Symptoms (such as shortness of breath, swelling, cough)
Recent or past illnesses (such as heart attack, viral illness, high blood pressure, diabetes)
Effort tolerance (how much exercise can you do before becoming tired)
Ability to sleep flat and ability to perform routine activities
The following parts of the physical examination are most helpful in diagnosing congestive heart failure:
Measuring blood pressure (to detect high blood pressure) and pulse rate (to detect any abnormal heart rhythm)
Checking the veins in the neck for swelling or evidence of high blood pressure in the arteries of the eye
Listening to breathing (crackles can be heard in the lungs when they are congested with fluid) and heart sounds (an extra heart sound can be heard in a failing heart and valve lesions will result in blood flow turbulence heard as murmurs)
Checking the abdomen for swelling due to fluid build-up and for enlargement of or tenderness over the liver
Checking the legs and ankles for swelling due to fluid build-up
Measuring body weight (rapid fluctuations are usually associated with change in body water content)
If the person has symptoms typical of heart failure, the physical examination may be all that is needed to make the diagnosis. However, additional tests will be needed to determine the specific cause and type of heart failure and the extent of damage to the heart.
Laboratory tests
In some cases, the results of laboratory tests may reveal a cause or trigger of heart failure or give an indication of its severity. These tests include:
Full blood count detects the presence of anaemia (low red blood cell count), which can cause or aggravate heart failure.
Urea, creatinine and electrolyte level measurement a measure of kidney function that indicates how well the heart is perfusing the kidneys; also indicates whether fluid retention is primarily due to a kidney rather than a heart problem.
Liver function test measures various enzymes released from a damaged liver when congested; also measures the levels of a protein called albumin in the body (low levels of albumin can also lead to fluid build-up).
Blood glucose measurement high levels may indicate diabetes.
Thyroid function tests abnormal thyroid function can lead to heart damage.
Urine analysis protein or red blood cells in the urine may indicate kidney damage.
Electrocardiogram
An electrocardiogram (ECG) is a recording of the electrical activity of the heart. This test is helpful in evaluating the heart and can show an abnormal heart rhythm, enlargement of the heart chambers and evidence of poor blood supply to the heart muscle.
Chest X-ray
A chest X-ray (CXR) produces a photographic image of the heart and lungs. The picture is created using rays of energy that pass through the body and project an image on a film. An X-ray can show information about the size and shape of the heart (the heart usually enlarges in congestive cardiac failure) and evidence of congestion in the lungs.
Other findings may suggest that shortness of breath is caused by lung disease rather than heart failure.
Echocardiography
Echocardiography (Echo) is an investigation that uses high-pitched sound waves sent through a device called a transducer to produce a live, moving image of the heart on a screen. (This technology, also called ultrasound imaging, is the same as that used to view an unborn baby inside the mother's womb.) Echocardiography is used to evaluate the ability of the left ventricular chamber to relax, fill with blood and then pump the blood out to the body. A measurement of the amount of blood pumped out of the left ventricle with each heartbeat is obtained and indicates the severity of left ventricular dysfunction. Echo also helps evaluate heart size and heart valve function.
Radionucleotide ventriculogram
During a radionucleotide ventriculogram, a radioactive substance (radioisotope) is injected into a vein. This substance then circulates in the blood stream to the heart. Due to its radioactive nature, special screening devices can detect the substance as it moves through the body. Ventriculography evaluates how effectively the left ventricle is pumping and measures the percentage of blood pumped out of the left ventricle with each heartbeat.
Treatment
In some patients, congestive heart failure can be improved and even cured by treating the underlying disease process. An example of this would be valvular heart surgery in a failing heart with a valve abnormality.
However, in many other patients the underlying problem cannot be solved. The goal of treatment is therefore to prevent further damage to the heart and to improve its pumping ability. This is usually achieved with medication and lifestyle modification, but surgery is being evaluated as another treatment option.
Medications
Angiotensin-converting enzyme (ACE) inhibitors
Angiotensin Converting Enzyme (ACE) inhibitors, Angiotensin Antagonists, Beta blockers and Spirinolactone are drugs used in the treatment of heart failure, which have been proven in clinical trials, not only to improve symptoms, but also the long-term outcome (prognosis) in patients with heart failure. Diuretics and Digoxin, while improving symptoms, do not influence the long-term prognosis.
They're the only drugs clearly proven in various medical trials to help people with the disease feel better and live longer. The drugs include captopril, enalapril and ramipril.
ACE inhibitors help the failing heart by relaxing the arteries in the body. This allows blood to flow from your heart more easily. They also decrease sodium and water retention.
ACE inhibitors cause an irritating cough in about 20% of people taking them. But it may be best to put up with the cough, if you can, to gain the medications' benefits.
Diuretics
Often called "water tablets", diuretics make you urinate more frequently and prevent fluid from collecting in your lungs and elsewhere in your body. An example of a commonly prescribed diuretic is furosemide.
Digoxin
Digoxin, also called digitalis, increases the strength of your heart muscle contractions. While digoxin doesn't improve overall survival rates, it reduces heart failure symptoms and improves your ability to function with the condition.
Beta-blockers
Beta blockers approved for the treatment of congestive heart failure are carvedilol, metoprolol and bisoprolol, although carvedilol appears to be the drug of choice. These agents reduce the risk of death from progressive pump failure as well as the risk of sudden death.
Angiotensin II antagonists
Angiotensin II (AT-II) antagonists (losartan, valsartan) work similarly to ACE inhibitors but don't cause a persistent cough. Recent trials suggest these agents to be of similar efficacy as ACE inhibitors in the treatment of heart failure, but in general there use is limited to those intolerant of ACE inhibitors.
Life-style changes
The following life-style changes are important in controlling the symptoms of heart failure and may play a role in preventing disease progression:
Restriction of salt intake
Salt, but more specifically the sodium contained in it, causes you to retain fluids. You also need to be careful when using salt substitutes.
Limiting fluid intake
If you have congestive heart failure your body will retain excess fluid. In order to minimise fluid build up and reduce the amount of diuretics you need, it is important to restrict your fluid intake to less than 2 litres per day.
Limiting alcohol intake
If it is thought your heart failure is due to excess alcohol intake, it is very important to abstain totally from all alcohol. Continued use will lead to worsening heart failure. Patients with heart failure from other causes should limit their alcohol use to one or two units per day.
Weight monitoring
You should weigh yourself every morning. Rapid weight increase of 1 or 2 kg may indicate excessive fluid retention. Contact your doctor if this happens, because your medication may need to be changed.
Exercise
Exercise was once contra-indicated in people with heart failure, but studies have shown that moderate exercise helps your heart pump more efficiently and reduces the demands on your heart muscle. Before you start exercising, talk to your doctor about the best type of exercise for you and warning signs that you've done too much and should stop.
Surgical procedures
Researchers continue to search for new and better ways to treat congestive heart failure. Some surgical procedures being studied include:
Heart pumps
Mechanical heart pumps, called ventricular assist devices, are implanted into your chest and attached to your weakened heart to help it pump. This is a temporary procedure used to keep heart transplant candidates alive while waiting for a donor heart.
"Heart reduction" surgery
As the left ventricle becomes weaker, it enlarges further. This compromises its pumping ability. A procedure called partial left ventriculectomy, or heart reduction surgery, can sometimes be performed. This involves removing a portion of your enlarged heart muscle and "remodelling" your heart to its near-normal size and shape. In theory, this should help your heart pump more efficiently. The potential role of this operation is not yet well understood, but research continues.
"Wrap-around" surgery
In the "wrap-around" procedure, called cardiomyoplasty, a piece of back muscle is removed and wrapped around your heart. It is then stimulated electrically to contract rhythmically with your weakened heart muscle. Again, what role, if any, this procedure may have in treatment is not yet known.
Heart transplant
If all other treatment modalities fail, a heart transplant is an option. Survival and quality of life following a transplant are excellent, but there's a shortage of donor hearts and the recipient will be on life-long immuno-suppressive treatment. Candidates for transplantation are typically younger patients (under 65 years of age) who are free of other serious diseases and whose other vital organs are healthy.
Xenotransplantation
Researchers are exploring the possibility of transplanting genetically manipulated pig hearts into humans with congestive heart failure. Clinical trials could begin in the three to five years in the United States.
Prevention
The best way to prevent congestive heart failure is to adapt a healthy lifestyle that protects your coronary arteries against atherosclerosis (build-up of cholesterol, and narrowing and hardening of the arteries). It is also important to control medical conditions such as high blood pressure and diabetes.
Atherosclerosis in the heart's blood vessels (coronary artery disease) is a leading cause of congestive heart failure. To reduce your risk of developing atherosclerosis:
Don't smoke. If you do smoke, quit. Smoking greatly increases your heart disease risk.
Watch your cholesterol level. If it is over 200 mg/dl (5.17 mmol/L), follow your doctor's advice for lowering it. A low-cholesterol diet, exercise and quitting smoking will help keep your cholesterol low.
Keep your blood pressure low. If your blood pressure is over 140/90 mm Hg, you run a higher risk of heart disease. Exercising, limiting alcohol intake and controlling stress will help keep your blood pressure in the healthy range.
Exercise regularly. Apart from the benefits mentioned above, it will help control your weight and your stress levels, all of which will help keep your heart healthy.
Control diabetes by taking your medications as directed.
Reviewed by Dr Mark Abelson MBBCH, MRCP(UK), FCP(SA)
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