What is endocarditis?
Endocarditis (infectious endocarditis) refers to an infection of the inner lining of the heart (the endocardium) and/or the valves that are covered with it. The source of the infections and inflammation can be from anywhere, such as bacteria of the mouth, cuts on the skin, contaminated needles and inadvertent injection of talc in IV drug abuse, sexually transmitted infections, etc. The mouth is an important concern, since poor dentition is a risk factor for endocarditis.
Bacteria–primarily Staphylococcus and Streptococcus–are particularly compatible with damaged or artificial heart valves, to the point that the incidence of endocarditis has fallen with the decrease in Rheumatic fever over the decades. Fungi can also cause endocarditis.
Whether heart valves are healthy or damaged, bacteria that take hold there cause new and/or further damage, leading to functional heart disease when the valves cannot perform optimally to prevent back flow into the heart chambers during each contraction.
Risk Factors for Endocarditis
- Age >60
- Male gender
- IV drug abuse
- Poor oral hygiene, poor dentition, or dental infection; alternately, excessive brushing and flossing; also, dental procedures involving instrumentation
- Structural abnormalities of the heart, such as congenital heart disease, valve damage from prior infection or surgical repair/replacement; mitral valve prolapse with mitral regurgitation, aortic valve disease, and other valvular disease
- Prosthetic valve replacement
Symptoms of endocarditis include fever (90%), anorexia and weight loss, headache, myalgia and arthralgia, abdominal pain, dyspnea, cough, and pleuritic pain.
Signs of endocarditis include heart murmurs (85%), enlarged spleen, and skin petechiae (splinter hemorrhages).
Complications of Endocarditis
Cardiac (up to 50%): heart failure, pericarditis, valve damage (valvular insufficiency) and valve abscess, and infectious emboli throughout the body.
Systemic (up to 25%): sepsis from infectious emboli (especially Staphylococcus and fungi), metastatic abscess (spleen, kidneys, brain, or lungs); fungal endocarditis can create mycotic aneurysms in the arterial (including cerebral) vessels.
Central Nervous System (up to 40%): stroke, brain abscess, and meningitis.
The seriousness of such complications contributes to an infectious endocarditis mortality rate of up to 25%.