The heart has two halves, a left and a right, each with two chambers - the atrium and the ventricle. Between the chambers are the heart valves which ensure the blood runs only in one direction.
There are also heart valves situated between the ventricles and the major arteries - the aorta and pulmonary artery - where they have the same function.
Failure in a valve in the left side of the heart - the aortic or the mitral valve - results in left-sided heart failure. This leads to an accumulation of fluids in the lungs, or pulmonary edema.
Valve diseases of the right side of the heart - the pulmonary and tricuspid valve - are rare but can occur as the result of some forms of congenital heart disease or long-term left-sided heart failure.
Right-sided heart failure is characterised by fluid accumulation in the body, particularly in the legs, abdominal cavity and the liver.
Malformation of the heart valves can be divided into two categories: narrowed (stenosed) valves and leaking (regurgitant) valves - or a combination of both.
What causes heart valve disease?
These may be due to:
- congenital abnormality
- degeneration through atherosclerosis (aortic stenosis only)
- damage from rheumatic fever
- excessive calcification in old age (aortic stenosis only).
These may be due to:
- bacterial infection or inflammation of a valve
- excessive floppiness of the leaflets (mitral valve prolapse)
- enlargement of the heart or aorta - the main blood vessel into which the left ventricle pumps.
What does a malformation of the heart valve feel like?
In mild cases there are no symptoms and generally no cause for worry, although antibiotic treatment to prevent the risk of a valve infection is recommended, for example to cover a dental procedure when there is a chance that there will be some bacteria introduced into the bloodstream temporarily.
Serious cases may not be evident for a long time either. There may be no symptoms, even though the heart is already under strain. In cases of stenosis of the aortic valve, it is important to be aware of the following possible symptoms, since this condition may result in sudden death:
- dizziness or a faint brought on by physical effort
- shortness of breath
- angina (chest pain) on exertion.
How does the doctor make the diagnosis?
The diagnosis is based on the patient's case history, examining the heart and by using a stethoscope to listen for any abnormal sounds or murmurs coming from the heart valves or heart muscle.
To find out if the malformation is serious, the doctor can refer the patient for further examinations, such as echocardiography and cardiac catheterisation.
This is an ultrasound scan of the heart. It gives an accurate measure of the degree of the leak and/or stenosis, whether the heart's pumping ability is impaired and can often give the exact cause of the valve disease.
The pressure in the atria, the ventricles and the great vessels - the aorta and pulmonary artery - is measured using catheters. Through injecting a dye which is visible on an X-ray, the doctor can also assess the degree of the leakage.
What can the doctor do?
The doctor can try to find the cause of the valve malformation, or refer the patient to the hospital for further investigation and possible treatment.
Which medications are used?
For prevention of infection
An abnormal valve is more likely to become infected with bacteria. This could occur, for example, if bacteria enters the bloodstream during surgical procedures, cardiac catheterization or dental treatment.
Preventive treatment with antibiotics (such as amoxicillin) is suggested if the patient needs to have any kind of treatment likely to introduce bacteria into the blood.
For treatment of symptoms
Diuretics help the body to excrete excessive salts and fluid through the kidneys:
- loop diuretics, which have a strong effect, are the main type used
- potassium-sparing diuretics may be given to complement the loop diuretic
- a thiazide-diuretic may be used as an additional diuretic if heart-failure symptoms are severe.
Medicines to improve a poor heart function such as ACE inhibitors or angiotensin-II receptor agonists (ARAs), help the heart work more effectively in the presence of a leaky valve.
Warfarin may be used to 'thin' the blood if there is an increased risk of blood clot development.
Nitrate-preparations and vasodilators to relax and dilate the arteries. These are used if the patient cannot tolerate ACE inhibitors or ARAs.
Further development and treatment possibilities
A serious untreated malformation can lead to heart failure. Significant valve defects can be treated surgically either by replacement with an artificial valve or by repairing the affected valve (usually specific to the mitral valve).
Following an operation of this type, it is necessary to take anti-clotting medication such as warfarin - sometimes permanently, depending on the type of surgery performed and the type of valve replacement.
If the patient is unsuitable for surgery, because of another coexisting illness or end-stage heart failure, medication can diminish heart failure symptoms.
Based on a text by Dr. Sabine Gill and Dr. Steen Dalby Kristensen