Acute Endocarditis: Symptoms, Causes, Mortality, Treatment, Surgery, and Characteristics

Acute Endocarditis (급성 경동맥내막염)

1. Definition

Acute endocarditis is a condition characterized by rapid inflammation of the inner lining (endocardium) of the heart or its valves, primarily caused by bacterial infection. This condition can cause serious damage to the heart's structure and can be life-threatening if left untreated. Acute endocarditis is a serious condition where infection occurs rapidly, leading to quickly appearing symptoms and potentially causing systemic complications. Inflammation primarily occurs in the heart valves, impairing their function or causing damage.

2. Characteristics

The characteristics of acute endocarditis are rapid progression and serious complications. The main characteristics are as follows:

• Rapid Progression: Acute endocarditis progresses rapidly. Infected bacteria invade the endocardium, damaging the valves and rapidly affecting heart function. This can lead to heart failure, heart valve rupture, blood clot formation, and various other problems.
• Infectious Cause: Most cases of acute endocarditis are caused by bacteria, with Staphylococcus aureus being the most common causative agent. Other bacteria that can cause acute endocarditis include Streptococcus species and Enterococcus. These bacteria invade the endocardium through the bloodstream, causing inflammation.
• Infected Valve: Acute endocarditis causes rapid damage to the heart valves. This can prevent the valves from closing properly, or blood clots can form in the infected area, blocking blood flow. Rupture of the infected valve will severely impact heart function.
• Systemic Complications: Acute endocarditis can spread to other organs through the bloodstream, causing complications in the brain, lungs, kidneys, and other organs. These complications can be life-threatening.

3. Causes

The main cause of acute endocarditis is bacterial infection. It mostly occurs when bacteria enter the endocardium through the bloodstream. The main causative agents are as follows:

• Staphylococcus aureus: The most common causative agent in acute endocarditis, a staphylococcus bacterium that resides on the skin and mucous membranes. This bacterium is particularly more prevalent in individuals with abnormal heart valves (e.g., prosthetic valves) or drug users.
• Streptococcus viridans: A normal bacterial flora present in the oral cavity and upper respiratory tract, which can cause endocarditis due to dental procedures or oral infections.
• Enterococcus: Bacteria found in the intestines, frequently detected in cultures. This bacterium can cause endocarditis in individuals with abnormal heart valves.
• Other Causative Agents: Non-bacterial causes such as Candida (fungus) can also cause acute endocarditis, but this is rare.

3.1. Infection Routes

Acute endocarditis usually occurs in a state of bacteremia. This can occur through various routes:

• Dental Procedures: During dental treatment, bacteria from the oral cavity can reach the heart through the bloodstream.
• Surgery and Trauma: Infections from surgical procedures or wounds can enter the bloodstream and affect the endocardium.
• Intravenous Drug Use: Drug users or patients using shared needles have a higher likelihood of bacteria reaching the heart through the bloodstream.

4. Symptoms

Symptoms of acute endocarditis appear rapidly and may include high fever, fatigue, heart murmur, shortness of breath, and systemic infection symptoms. The main symptoms are as follows:

• Fever: Most patients experience high fever (over 38°C), which is an early symptom of infection. Fever can recur and intensify.
• Heart Murmur: Inflammation of the heart valves can cause a heart murmur. This can be easily detected with a stethoscope and is an unusual sound caused by the infected valve.
• Fatigue, Lethargy: Acute endocarditis has systemic effects, causing fatigue. Patients may find it difficult to perform daily activities.
• Shortness of Breath: If heart function is impaired, breathing may become difficult, leading to shortness of breath.
• Osler's Nodes (덩어리 형태의 병변): Small, painful nodules may appear on the fingertips or toes. This is because bacteria invade the blood vessels and cause inflammation.
• Bleeding: Small hemorrhagic spots (splinter hemorrhages) may appear under the fingernails.
• Other Symptoms: As the infection spreads throughout the body, complications such as stroke, pneumonia, and impaired kidney function may occur.

5. Treatment and Surgical Methods

Acute endocarditis requires immediate treatment. Treatment is divided into antibiotic treatment and surgical treatment.

5.1. Antibiotic Treatment

• Hospitalization: Acute endocarditis usually requires hospitalization for strong antibiotics. Antibiotics work to eliminate bacteria by entering the bloodstream and are administered through intravenous injection.
• Antibiotic Selection: The choice of antibiotic depends on the type of bacteria causing the infection. For infections caused by Staphylococcus aureus, antibiotics such as Methicillin and Vancomycin may be used. For infections caused by Streptococcus viridans, Penicillin is used.
• Treatment Duration: Treatment typically lasts 4-6 weeks and continues until the bacteria are completely eliminated.

5.2. Surgical Treatment

• Heart Valve Surgery: If the infection is severe and the heart valve is damaged, surgery may be necessary. Valve replacement or valve repair may be performed, which may lead to surgery involving the implantation of a prosthetic heart valve.
• Blood Clot Removal: If blood clots have formed in the heart, surgical intervention to remove them may be necessary. The clots must be removed to prevent them from blocking blood flow or spreading to other organs such as the brain or lungs.
• Treatment of Complications: If systemic complications (e.g., stroke, pulmonary embolism) occur, additional surgery or treatment may be needed to address them.