Infective Endocarditis: Common Risk Factors and Affected Heart Valves

Infective endocarditis is a serious infection that primarily affects individuals with weakened immune systems or underlying heart conditions. It most commonly occurs in patients who have undergone heart valve replacement surgery, elderly individuals with degenerative valve disease, intravenous drug users, and those who are bedridden for extended periods due to chronic illness or advanced age.

Which Heart Valves Are Most Frequently Affected?

The mitral valve is the most commonly affected valve in cases of infective endocarditis. This is closely followed by the aortic valve, with the tricuspid valve also being a frequent site of infection. The specific valve involved often depends on the underlying heart condition and the route of infection.

Types of Infective Endocarditis

Acute Infective Endocarditis

Acute infective endocarditis is characterized by a sudden and severe onset. It is most commonly caused by Staphylococcus aureus, a bacterium known for its aggressive nature and ability to rapidly damage heart valves. This type of infection requires immediate medical attention and intensive treatment.

Subacute Infective Endocarditis

Subacute bacterial endocarditis develops more gradually and tends to progress over weeks or even months. It is most often associated with viridans streptococci, bacteria that are part of the normal oral flora. This form of the disease may present with more subtle symptoms, making early diagnosis more challenging.

Understanding the Risk Factors

Recognizing the populations most at risk is crucial for early detection and prevention. Patients with prosthetic heart valves, congenital heart defects, or a history of previous endocarditis are particularly vulnerable. Additionally, individuals engaging in intravenous drug use face a significantly elevated risk due to repeated exposure to bloodstream infections.