Heart valve disease

 

Heart valve disease is when a valve in the heart is faulty. This can cause symptoms such as breathlessness and swollen ankles. Severe heart valve disease can result in permanent damage to the heart. Medicines can treat the symptoms, but some people will need surgery to repair or replace a faulty valve.

The heart valves

 

The heart is a muscular pump divided into two sides. The right side of the heart pumps blood to the lungs to load it with oxygen, and the left side pumps oxygenated blood around the body.

The heart has four valves. On each side there are two chambers - the ventricle and the atrium. Separating the chambers are heart valves. On the right, this is called the tricuspid valve, and on the left, the mitral valve.

There are also valves on each side between the heart and the major blood vessel taking blood away from the heart. On the right this is the pulmonary valve. On the left, between the left ventricle and the aorta, is the aortic valve.

Heart valves are made up of flaps of thin, strong, tissue attached to the heart with fibrous cords. They can only open in one direction.

The valves have two functions. They allow blood to flow through them smoothly and they prevent blood from leaking back against the flow.

 

Heart valve disease

 

There are two problems that can affect the heart valves.

-The valve may become narrowed, so blood cannot flow into the next chamber or blood vessel. This is called valve stenosis.

-The valve may not close properly, so blood leaks backwards in the wrong direction. This is called valve insufficiency or incompetence.

 

Causes of heart valve disease include:

 

- rheumatic fever during childhood - this disease is no longer common in the UK

- a congenital deformity - some people are born with a faulty valve

- coronary artery disease, when a blockage occurs in the arteries that supply blood to the heart

-a bacterial infection

- enlargement of the aorta

- aging - the valves become less flexible, stretched or torn

- injury to the heart

- a disease called cardiomyopathy, when the heart muscle becomes thickened

 

Symptoms of heart valve disease

 

Both valve stenosis and valve incompetence put extra strain on the heart. When a valve is stenosed, the heart has to work harder to get blood through it. When a valve is incompetent, the heart has to work harder to pump the required amount of blood around the body.

The blood behind the valve may also be under increased pressure. When this happens with the aortic valve (on the left), this can lead to a build-up of fluid on the lungs (pulmonary oedema). When this happens on the right-hand side, this can lead to a build up of fluid in the body, particularly in the legs.

The symptoms of valve disease depend on which valve is affected, and how severely. If there is only mild damage, there may be no symptoms.

 

If the valve disease is more serious, the symptoms can include:

 

- breathlessness during exertion

- waking up at night short of breath

- palpitations (irregular, fluttery heartbeat)

- angina (chest pain) because the blood vessels supplying the heart muscle are not getting enough blood

- swelling of the ankles or feet

- tiredness

- dizziness or fainting

 

Diagnosis

 

The GP will listen to a description of the symptoms and do a physical examination, including listening to the heart with a stethoscope. He or she will listen for a murmur, an extra noise, which can be caused by blood passing through a damaged valve.

If the GP thinks there may be a problem with the heart, he or she may refer you to a cardiologist (a specialist heart doctor), who can carry out more specific tests. These may include:

- an electrocardiogram (ECG), which records the electrical changes happening in the heart

- a chest X-ray

- an echocardiogram, an ultrasound scan that produces a picture of the inside of the heart

- a cardiac catheterisation (angiogram), where a small tube (catheter) is threaded up to the heart through an artery in the groin. A dye that shows up on X-rays is injected and X-rays are taken to produce an image of the blood flowing through the heart

 

Treating heart valve disease

 

Treatment depends on what is wrong with the valve and how serious the problem is. Medicines may be prescribed to relieve the symptoms:

- diuretics - these help to reduce swelling by encouraging the body to get rid of excess water in the urine

- ACE-inhibitors - these help the heart work more effectively by relaxing blood vessels and so improving blood flow

- digoxin - stabilises the heart rhythm and helps the heart pump harder

 

Heart valve surgery

 

If the valve disease is serious, medicines may not be enough to control the symptoms. In this case, heart valve surgery may be recommended to prevent permanent damage to the heart. The two types of surgery are valve replacement or valve repair.

Valve replacement involves replacing the faulty heart valve with a prosthetic (artificial) valve. This may be a mechanical or a biological valve (made from human or animal tissue).

Mechanical valves have the advantage of lasting a lifetime. However, they require the patient to take blood thinning drugs for the rest of their life, which can increase the risk of bleeding in the body. This can be especially serious if it happens in the brain (this is called a haemorrhagic stroke).

Prosthetic valves made of human or animal tissue do not require blood thinners to be taken, but they need to be changed every 10-15 years because they wear out.

Valve repair is usually only recommended for mitral valves which leak, but are not damaged seriously.

Both procedures are performed under a general anaesthetic. This means the person is asleep and will feel no pain. The surgeon makes a cut, about 25cm (10") long, down the middle of the breastbone (sternum) and opens the ribcage to reach the heart. Medication is used to stop the heart temporarily. The blood is then rerouted to a heart-lung (bypass) machine. This takes over from the heart and lungs, adding oxygen to the blood and maintaining the circulation.

The damaged valve is replaced or repaired. The surgeon restarts the heart and the blood is allowed to flow back through the heart. The operation lasts around three to five hours.

Deciding to have heart valve surgery

In order to give informed consent, anyone deciding whether or not to have surgery needs to be aware of the possible side-effects and the risk of complications.

 

Side-effects

 

Side-effects are the unwanted but usually temporary effects of a successful procedure. Examples include feeling sick as a result of the general anaesthetic and painkillers.

 

Complications

 

Complications are unexpected problems that can occur during or after the operation. Most people are not affected, but the main possible complications of any surgery are excessive bleeding, infection or an unexpected reaction to the anaesthetic. Complications may require further treatment such as a further operation to stop bleeding, or antibiotics to treat an infection.

On average, about five percent of people having a heart valve replacement do not survive surgery or die shortly afterwards. But it's important to consider that having no treatment, or having an alternative treatment, may be a higher risk.

The surgeon will explain how the risks apply in each case. If you smoke, giving up smoking will make the operation easier and safer