Cardiovascular system Endocarditis

The infectious endocarditis is a rare condition where one or more heart valves become infected. The valves help the blood to circulate inside the heart and to the pulmonary and aorta arteries; they open and close themselves aiming to enable the blood flow in only one direction.

It is a severe disease, with hard diagnosis. People presenting congenital or acquired (rheumatic fever) heart and valve issues and other diseases such as cirrhosis, alcoholism, and drug abuse are those that are more risked to present the disease. People presenting an artificial cardiac prosthesis or a previous endocarditis are more risked to present a new infection.

Figure 1. Normally functioning heart valves

Referring to the symptoms, fever, chills, night sweating, weakness, appetite and weight loss, and heart failure might occur. As the symptoms are vague and non-specific, it is hard to make an early diagnosis, and this is usually made after several weeks.

The most common cause is a dental treatment. There is a great number of bacteria in the mouth, which, depending on the degree of treatment handling, can enter in the blood circulation and be lodged in a heart valve. Other infection by bacteria (such as a boil) can originate the entrance of bacteria in the circulation and trigger an endocarditis. The patients with highest risk must perform a prophylaxis (prevention) with antibiotics during the procedure, when the physician indicates.

An endocarditis must be treated with antibiotics. Nowadays, most patients recover only with a prolonged treatment with antibiotics (6 weeks). A valve surgery might be needed when the valves become very damaged by the infection.


When there is need for surgery, the procedure for an endocarditis is the valve surgery. A valve plastic surgery can be performed in some cases and, when the disease is more advanced, a valve replacement with a prosthesis is indicated.

There are several available prosthesis types. Metallic and biological prostheses are the most used ones in our context.

The biological prostheses are made of a treated animal (pig or ox) tissue. These prostheses have the non-obligatoriness of using anticoagulant medicines as a potential advantage, but have a limited durability.

The metallic prostheses are made of a carbon alloy, present great durability, and have very little structural issues, but there is need for using anticoagulant drugs for life. Such medicine (warfarin) is taken as a tablet and thins the blood, so preventing the clot formation in the valves.

In both prosthesis types, the endocarditis (valve infection) prevention with antibiotics must be performed before each procedure that causes a potential entrance of bacteria in the blood (for example, dental or urinary procedures).

Figure 2. Heart valve prostheses


A good mouth hygiene and visits to the dentist at least once yearly are important. An antibiotic treatment can be recommended, depending on the procedures.

The use of antibiotics is recommended for patients with artificial heart valves or other risk factors in the following procedures:
– dental procedures that cause bleeding, such as tartar removal, extraction, periodontal surgery, implants, and root canal treatment;
– removal of tonsils or adenoids;
– bronchoscopy with stiff bronchoscope;
– sclerotherapy of esophageal varicose veins;
– esophageal dilatation;
– cystoscopy (urethral catheterization) and urethral dilation;
– prostate gland surgery and biopsy of urinary tract;
– lithotripsy;
– ureteral instrumentation;
– vaginal delivery complicated by infection.

The antibiotic to be used in each case and its dosage must be indicated by the physician.