Heart conditions - endocarditis

Endocarditis is an infection of the heart valves or the endocardium, the membrane that lines the inner surfaces of the heart. It tends to occur in people who already have certain heart conditions. The condition is also known as infective endocarditis or bacterial endocarditis.

Without treatment, the infection can severely damage or even destroy the heart valves. Some dental and surgical procedures raise the risk of endocarditis because they can introduce bacteria into the bloodstream.

Symptoms of endocarditis#

The symptoms of acute bacterial endocarditis appear within a few weeks of infection. The symptoms of subacute bacterial endocarditis may take weeks or months to develop. General symptoms can include:

• fever and chills
• tiredness and lack of energy
• loss of appetite
• a persistent cough
• general aching throughout the body
• abnormal heart rhythms, such as a slow or rapid (tachycardia) heartbeat
• a heart murmur
• faster breathing

How endocarditis develops#

Usually an infection elsewhere in the body lets bacteria circulate in the blood, a state known as bacteraemia. These bacteria can settle on areas of the heart that are already damaged or diseased.

Prosthetic devices, such as artificial heart valves, can be vulnerable to infection because the immune system does not recognise them as part of the body and may not defend them as strongly.

The infection causes inflammation and blood clots, and the body’s healing response leads to scarring. A scarred endocardium or heart valve is then more vulnerable to future infections.

Complications of endocarditis#

Endocarditis can cause serious complications, including:

• reduced function of a heart valve
• blocked blood vessels, when a clot breaks free from the endocardium, lodges in a blood vessel and reduces blood flow to nearby tissues or organs
• spread of the infection to other parts of the heart
• spread of the infection to other parts of the body, such as the brain

Risk factors for endocarditis#

Endocarditis rarely affects people with a healthy heart, but some people have a higher risk. Risk factors include:

• congenital heart defects
• previous surgery to correct heart defects
• surgical devices such as a pacemaker, artificial heart valve or shunt
• rheumatic heart disease
• a previous episode of endocarditis
• intravenous drug use, even without a history of heart disease

Some congenital heart defects, such as a ventricular septal defect, can be successfully repaired with surgery so that the increased risk of endocarditis is removed. If you have a heart condition, ask your doctor whether you are at risk of endocarditis.

Procedures that may trigger endocarditis#

Short-term bacteraemia can be caused by certain dental and surgical procedures, including:

• professional tooth cleaning
• any dental procedure likely to cause bleeding, such as a tooth extraction
• heart surgery
• intravenous lines used during or after surgery
• examination of the lungs with a rigid bronchoscope
• removal of the tonsils (tonsillectomy) or adenoids (adenoidectomy)
• urinary tract surgery
• gastrointestinal or gall bladder surgery
• prostate surgery

If you are at risk, it is important to tell your dentist or surgeon. You may be prescribed antibiotics to take before the procedure to reduce the risk of bacteraemia. You may also wish to carry a medical card noting your increased risk in case of a medical emergency.

Diagnosis of endocarditis#

Tests used to diagnose endocarditis include:

• a physical examination
• a review of your medical history
• urine tests
• blood tests
• diagnostic imaging, such as ultrasound

Treatment for endocarditis#

Treatment options include:

• a four to eight-week course of antibiotics
• blood-thinning medication, such as aspirin or warfarin, to treat blood clots
• surgery to repair or replace severely damaged heart valves or destroyed devices such as prosthetic heart valves

Key points#

• Without treatment, the infection can severely damage or even destroy the heart valves.
• The symptoms of acute bacterial endocarditis appear within a few weeks of infection.
• The symptoms of subacute bacterial endocarditis may take weeks or months to develop.
• General symptoms can include fever, tiredness, loss of appetite and a persistent cough.
• Usually an infection elsewhere in the body lets bacteria circulate in the blood (bacteraemia).

Where to get help#