Long-standing inefficient pumping action of the heart, leading to poor circulation of blood and accumulation of fluid in tissues
- More common over the age of 65
- Slightly more common in males
- Genetics and lifestyle as risk factors depend on the cause
In chronic heart failure, the heart is unable to pump blood around the body effectively. This problem leads to a gradual build-up of fluid in the lungs and body tissues. Chronic heart failure is a common progressive condition that may be so mild at first that symptoms go unnoticed. It mostly affects people over 65.
Although the term “chronic heart failure” may appear to imply a life-threatening disorder, it can often be treated, and people who have mild chronic heart failure can live for many years. However, the condition may limit physical activity.
At first, one side of the heart may be predominantly affected, and, in these circumstances, the condition is termed right- or left-sided heart failure. Right-sided heart failure leads to ankle swelling and accumulation of fluid throughout the body. Left-sided heart failure causes fluid to accumulate in the lungs. Fluid in the lungs due to left-sided failure usually rapidly leads to right-sided failure, and the combination of the two, known as congestive heart failure, is the most common form of chronic heart failure.
What are the causes?
Any condition that causes damage to the heart can lead to chronic heart failure. Whether the right or left side of the heart is first affected depends on the cause. In 8 out of 10 cases, chronic heart failure is caused by coronary artery disease, in which the blood supply to the heart muscle is reduced. Persistent high blood pressure (see Hypertension) can lead to chronic heart failure because the heart works harder to pump blood through vessels in which pressure is abnormally high. These disorders initially produce left-sided heart failure.
Failure of the right side of the heart is a common complication of chronic lung disease, particularly chronic obstructive pulmonary disease.
Other possible causes of chronic heart failure are heart valve disorders and dilated cardiomyopathy. In rare cases, chronic heart failure may be due to anaemia, the hormone disorder hyperthyroidism, or extreme obesity. People who have diabetes mellitus are also at risk of developing the condition.
What are the symptoms?
The symptoms develop gradually, are often vague, and may include:
Palpitations (awareness of an abnormal heartbeat).
Shortness of breath that is worse during exertion or when lying flat.
Loss of appetite.
Swelling of the feet and ankles.
In some cases, confusion.
People with chronic heart failure may also have sudden attacks of acute heart failure, with symptoms of severe shortness of breath, wheezing, and sweating. These attacks usually occur during the night. Occasionally, acute heart failure develops if the heart is put under additional strain due to a heart attack or an infection. Acute heart failure needs immediate hospital treatment.
How is it diagnosed?
If chronic heart failure is suspected, you may have electrocardiography (see ECG) to assess the electrical activity of your heart. You may also have echocardiography to image the heart and check its function. A chest X-ray may show signs of heart failure, such as an abnormally large heart or excess fluid in the lung tissue.
Your doctor may arrange for further tests to investigate the underlying cause of heart failure. For example, you may have coronary angiography to diagnose narrowing of the coronary arteries or blood tests to check for anaemia or an overactive thyroid gland.
What can I do?
If you have chronic heart failure, you should avoid strenuous exercise and stress. Regular gentle exercise, such as walking, should help if you have mild or moderate chronic heart failure. If you smoke, stop immediately. If necessary, try to lose excess weight to avoid putting unnecessary strain on your heart (see Are you a healthy weight?). You should also avoid salty foods, which can encourage your body to retain fluid.
How might the doctor treat it?
Your doctor will probably prescribe diuretics, which help to remove excess fluid and salt from your body by stimulating the kidneys to increase urine production. He or she will probably also prescribe ACE inhibitor drugs or angiotensin II blockers, which cause blood vessels to widen and reduce the workload on the heart, as well as reducing salt and water retention; and a beta-blocker to improve the efficiency of your heart muscle in the longer term (although you may not be prescribed a beta-blocker if you have asthma or arterial disease in your legs). In addition, you may be treated with digoxin (see Digitalis drugs) or other drugs, which also increase the efficiency of the heart. If diagnostic tests show narrowing of the coronary arteries, your doctor may advise coronary angioplasty and stenting.
You may also be treated to help prevent progression of any underlying disorder. For example, if you have coronary artery disease, you may be advised to take a daily dose of aspirin (see Drugs that prevent blood clotting), which reduces the risk of a heart attack. If you have an irregular heart rhythm or if your heart is severely enlarged, you may be treated with warfarin to reduce the risk of blood clots forming in the heart. If an ECG shows the electrical activity of your heart’s conducting system is very slow, your doctor may recommend that you have a special type of pacemaker called a biventricular pacemaker (see Cardiac pacemaker) fitted. This type of pacemaker increases the efficiency of the heart by improving the synchronization of contractions of the heart chambers. Whatever the details of your treatment, your doctor will monitor your heart condition and adjust your medication as needed.
In some cases, drug treatment may not be effective, and a heart transplant may be considered if a person is otherwise in good health.
What is the prognosis?
Treatment is usually initially successful in relieving symptoms and improving quality of life. However, in most cases, the underlying cause cannot be treated effectively. As a result, heart failure becomes progressively more severe, and symptoms are then difficult to control with drugs. In about half of these cases, the condition is fatal within 2 years.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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