Valve disease

This book is primarily about heart health and coronary artery disease. Sometimes heart valves become diseased, so a brief account of valve problems and their treatment is provided here.

The heart contains four valves which are designed to make sure that the blood flows one way only (see Figure 1.2 on p. 6). Disease of the valves will distort the normal function of the heart. The two valves that are the most important are the mitral and aortic valves and these are the most commonly affected (see Chapter 1 for information on anatomy). Sometimes both can be affected at the same time. Each year 5000 people in the UK have valve surgery.

Two disorders can sometimes affect the aortic and mitral valves:

• they can leak (this is called incompetence);

• they can narrow (this is called stenosis).

The aortic valve normally has three flaps (leaflets) but some people are born with two and this causes early wear and tear. The normal three-leaflet valve may also harden up or become leaky with age. This can occur independently of coronary artery disease.

CAUSES

I have been diagnosed with valve disease. What do you think is likely to have caused it?

There are several causes of valve disease.

• Mitral stenosis (narrowing) can be caused by rheumatic fever. This condition, usually experienced in childhood or teens, can inflame the valves and lining of the heart, leaving permanent damage.

• Mitral incompetence (leaking) may be the result of rheumatic fever, bacterial infection (see below), a weakness of the valve supports causing the leaflets to flop backwards, or a narrowing of the coronary arteries.

• Aortic stenosis may be due to rheumatic fever, being born with an abnormal valve (congenital) or age (wear and tear).

• Aortic incompetence may be due to rheumatic fever, high blood pressure, bacterial infection, age, or being born with an abnormal valve.

SYMPTOMS

How will I recognise valvular disease?

If the aortic valve narrows, this can cause angina, breathlessness and blackouts, whereas, if it leaks, it usually causes the heart to enlarge and breathlessness then follows. If you feel tired and breathless on exertion, it is probably a good idea to go to the doctor for an opinion or tests. Valve disease may cause heart failure (see Chapter 5).

A severe mitral valve leak or narrowing will also cause breathlessness.

Both valves can become infected (see the section Infection below).

Does the fact that I have valve disease mean that there is a greater strain on my heart?

Yes. As a result of either narrowing or leaking, or both, the abnormal valves increase the work that the heart has to do. If the valve is narrowed, the pump must generate higher and higher pressures to get the blood through. If the valve leaks, the pump must put out more blood with each beat: it must pump out the 5 litres that the body needs each minute plus the volume that has leaked back.

TESTS

I have been asked to go for tests to see if I have valve disease. What will these involve?

The doctor can usually hear heart murmurs and will confirm the diagnosis with echocardiography (see Chapter 5). Sometimes a murmur is heard and a problem detected by chance. The echo-cardiogram provides a comprehensive picture of your heart, telling us about any valve leaks or narrowing and their severity. If your valve condition is not too bad, it can be watched by the echocardiogram at 12- or 6-monthly intervals. If the echo identifies a severe problem, you will be offered further investigations and possible surgery.

TREATMENT

Valve conditions that are not severe can initially be treated medically. Diuretics (water tablets: see Chapter 2) are used to relieve breathlessness; digoxin may be used if there is atrial fibrillation (Chapter 6), when warfarin will also be used. If the main problem is a leaky valve, ACE inhibitors (see Chapter 2) may be used to try to reduce the leak. They act to open up the arteries so that blood leaving the heart meets less resistance, with the idea being to make it easier for blood to flow forwards rather than leak backwards.