Prosthetic valve endocarditis – When bacteria inflame inflame the lining of the heart

Some of us replacement heart valve patients had their natural valves replaced as a result of acquired infectious endocarditis.

The main cause of infectious endocarditis is a compromised immune system. Triggers for this weakened state include diseases such as diabetes, and excessive alcohol intake.

If bacteria (e.g. staphylococci or streptococci) find their way into the body, e.g. following removal of dental plaque or through abscesses or injury, they attach themselves to the delicate heart valves. The heart valves (aortic, mitral, tricuspid or pulmonal valves) do not have blood vessels of their own, so that the body’s policing system, the white blood cells, cannot effectively deal with the bacteria. The accumulations of bacteria which eventually form on and around the heart valve increasingly prevent it from opening and closing properly. The valve ultimately ceases to function.

The clumps of bacteria or damaged parts of the natural heart valve may become detached and flow through the systemic circulatory system, often leading to a fatal outcome. By this route they can reach any of the organs, causing sepsis (blood poisoning). If parts of the detached clumps are transported to the brain, then paralysis or other severe loss of function may result. Infectious endocarditis can arise suddenly and progress very dramatically. An important sign of the onset of infectious endocarditis is fast onset of fever. In the case of creeping infectious endocarditis, on the other hand, the body temperature is only slightly raised ? meaning that the condition can extend over many weeks or months.

The blood cultures which the doctor will request may give an indication of the type of bacteria involved. Nowadays the location of these bacterial clumps in the heart can be discovered by echo cardiography.

Prosthetic endocarditis

Prosthetic endocarditis, which all of us heart valve patients fear, is a rare disease. When it does occur, however, it takes a very dramatic course.

A sure sign is the often creeping onset of fever. The heart valve patient feels weakened by the chronic inflammatory process. Other symptoms the patient may notice are painless or painful nodules or skin discolorations along the edges of the fingers and feet. These are minor skin haemorrhages.

When prosthetic endocarditis is suspected, blood cultures will be prepared, which can tell the doctor what strain of bacterium is present.

In its advanced stages, prosthetic endocarditis may also be accompanied by cardiac arrhythmias.

Transoesophageal echocardiography (TEE) is an excellent diagnostic tool which the doctor can use to identify bacterial colonies in the area of the artificial heart valve early on.

Treatment of prosthetic valve endocarditis can only be carried out in a hospital, owing to the need for constant monitoring and medical equipment. Antibiotic treatment is a priority and must be continued over several months.

If, however, the infection cannot be brought under control, the artificial heart valve has to be replaced. The inflamed area around the heart valve is then also removed.

Prevention must be practised daily

If the body’s defences have been weakened through pre-existing disease, then particular consideration must be given to possible bacterial invasion. Even when the body is fit, however, the necessary antibiotic prophylaxis must be undertaken prior to surgery. Before and after dental treatment in particular – even if it is only to remove dental plaque – antibiotics must be taken. Tell your dentist that you are a heart valve patient.

Tonsillitis, otitis media, and inflammation of the kidneys, bladder or gallbladder are all conditions in which bacteria may find their way into the bloodstream and become lodged in the heart. Remember that the most susceptible part of your body is your mechanical heart valve, and that there is a high associated risk of endocarditis. If you are referred to a consultant or other doctor who does not yet know your medical history, let him know you are a heart valve patient. Produce your heart patient ID. This will indicate to the doctor that you have a high risk of contracting endocarditis.

PD Dr. med. Heinrich Körtke, Heart- and Diabetes-Center NRW, Bad Oyenhausen (Germany). (2004)