About Valvular Heart Disease

Valvular Heart Disease

The Heart Valves

A normal heart contains four main valves which regulate the direction of blood flow within the heart. The top two chambers of the heart, the atria, pass blood into the lower two chambers, the ventricles. The valves that separate the atria and the ventricles are the Mitral valve and the Tricuspid Valve. The ventricles then pump blood out of the heart. The left side of the heart pumps blood to the brain and the body through the aortic valve. The right side of the heart pumps bloods to the lungs, through the pulmonary valve.

The heart valves are thin pliable structures that open and close with every heart beat. A number of conditions can affect heart valves. These different conditions generally act on the heart valves by either becoming too ‘sticky’ or too ‘leaky’.

Damage to Heart Valves

Valves can become ‘sticky’ and open less well (‘stenosed’). In some cases, valves lose the ability to close fully and become ‘leaky’ (‘regurgitant’). Valves can be both stenosed and regurgitant and multiple heart valves can be affected at the same time. The process of heart valve damage involves a progressive calcification of the leaflets. There is also likely to be component of inflammation and lipid deposition.

Over time, a damaged heart valve will put strain on the heart, causing it to become less efficient at pumping blood. Heart failure can occur – where the heart has become swollen and less good at pumping blood. The common symptoms are breathlessness and fatigue on exertion. There may also be chest tightness or swelling of the legs.

Diagnosing Valvular Heart Disease

Heart valve disease is diagnosed by clinical examination which may reveal a ‘murmur’. A ‘murmur’ simply refers to a sound of blood flow within the heart. Detailed scans of the heart using Echocardiography are required to make a diagnosis of valvular heart disease. In most cases, patients with valvular heart disease will be monitored for many years before intervention is needed. Typically, patients are monitored with a yearly heart scan and clinic review. Cardiologists will observe for a number of different symptoms as well as changes in the heart valve and heart function.

Causes of Valvular Heart Disease

The most common cause of heart valve damage is natural ‘wear and tear’. This occurs slowly over a long time and can affect many older people. In some cases, people are born with valves that are more inclined to suffer wear and tear (this includes those with bicuspid aortic valves and those with severe mitral valve prolapse); this can manifest with valvular heart disease at mid-life. Others are born with more serious congenital heart problems and may require medical attention very early in life.

There are a number of other heart conditions that can affect the valves.

1. Rheumatic Heart Disease: childhood infections with bacteria that produce certain enzymes can cause a condition called rheumatic fever. The body can confuse the proteins made by the bacteria with those on the surface of the heart valves. This results in progressive inflammation of the heart valves and the leaflets become thickened and swollen. Over time, these ‘rheumatic’ valves can become stenosed, regurgitant or both. This condition has been reduced since the advent of modern antibiotics.
2. Endocarditis: Infection of the heart valves is called Endocarditis. Bacteria can settle on the heart valves and form small nodules called ‘vegetations’. The bacteria will cause severe damage to the valve and patients can become very sick. However, this condition can be very difficult to diagnose as the symptoms can be limited in the early stages. Blood tests, growing the bacteria in the laboratory and high quality of echocardiography is essential to making a diagnosis. Prolonged courses of powerful antibiotics are required to resolve the infection. In many cases, cardiac surgery may be required if there is significant valve damage or the infection is not resolving.

Treating Valvular Heart Disease

The treatment will depend on the underlying condition.

1. Close observation: patients with valvular heart disease will require regular echocardiography. In most cases, this will mean echocardiography on a yearly basis. Patients may require medications to help treat other heart conditions – for example, improving blood pressure or improving heart function.

2. Valvular Intervention: heart valves that are causing significant symptoms or are causing significant heart changes may require some form of intervention. This can be in the form of cardiac surgery or more minimally invasive treatment.

• Cardiac Surgery: This can be a major operation in which there may be either a cut to the sternum (chest bone) or a number of other cuts across the chest. The dysfunctioning valve may be repaired or replaced with an artificial valve. Replacement valves may be entirely metallic or be made of animal material. Heart valve surgery can also be performed at the same time as cardiac bypass surgery – which may be needed if the heart arteries are severely blocked.
• Minimally invasive approaches: Advances in medical technology have meant there are number of procedures that can be used in patients not suitable for open cardiac surgery. These technologies include transcutaneous aortic valve implantation (TAVI), percutaneous pulmonary valve replacement and the mitraclip. New technologies are being developed for tricuspid valve regurgitation.