Endocarditis

Disease Description (Causes and Symptoms)

• Definition summary: Endocarditis is a disease in which microorganisms (mainly bacteria and, more rarely, fungi) invade the endocardium (primarily the heart valves), causing inflammation and the formation of vegetations. It can be fatal if left untreated.
• Main causes:
  • Bacteria: Streptococcus (most common), Staphylococcus (related to surgery or prosthetic valves, including MRSA), some gram-negative bacteria, and antibiotic-resistant strains (such as VRE)
  • Fungi: Candida and others (fungal endocarditis forms large vegetations and has a poor prognosis)
• Pathophysiology summary: Microorganisms entering the bloodstream attach to damaged endocardium or the surface of prosthetic material and proliferate → vegetation formation → valve destruction, hemodynamic impairment, and embolism caused by fragments of the vegetation
• Main symptoms: Fever (most common), chills, weakness, loss of appetite, and weight loss (subacute); high fever, hypotension, and severe systemic symptoms (acute); shortness of breath (in heart failure); joint pain, headache, and petechiae on the limbs (related to embolism and immune reactions)
• Complications (summary): Valve regurgitation and heart failure; myocardial or perivalvular abscess and conduction-system damage (arrhythmia); systemic arterial embolism (including cerebral infarction); pulmonary embolism (in right-sided lesions); kidney involvement (glomerulonephritis); brain abscess; myocardial infarction caused by microemboli, etc.

Treatment Methods

• Basic principles: After identifying the causative organism, intravenous antibiotics to which the organism is susceptible are administered for a sufficient duration (usually 4–6 weeks) to eradicate the organisms even within the vegetation.
• Antibiotic treatment:
  • Targeted treatment based on the organism identified in blood cultures is necessary. (Empirical antibiotics may be started initially.)
  • Infections with resistant organisms such as MRSA and VRE, as well as fungal infections, are difficult to treat and require specialized management and long-term treatment.
• Representative indications for surgical treatment:
  • When the infection does not resolve despite antibiotic treatment (persistent bacteremia)
  • When a pericardial or myocardial abscess is present, or when severe valve damage causes heart failure
  • When a prosthetic valve infection or prosthetic-material instability is present (valve replacement is more likely to be necessary)
  • When there is a high risk of major embolism (large vegetation) or recurrent embolism
• Supportive treatment: Cardiovascular management for heart failure and shock, and specialized treatment for complications such as brain abscess
• Preventive measures:
  • For high-risk groups (prosthetic valves, previous endocarditis, certain congenital heart diseases, and valvular abnormalities after heart transplantation), prophylactic antibiotics are recommended for procedures involving bleeding or infection of the teeth, respiratory tract, skin, mucosa, or musculoskeletal system
  • Maintaining good oral hygiene during daily life is very important for prevention
  • Recommended dose for dental procedures (example): Adults, Amoxicillin 2 g orally (30–60 minutes before the procedure); children, 50 mg/kg (follow the doctor's instructions for the exact prescription)
• Precautions: Prosthetic-valve, fungal, and antibiotic-resistant infections have a poor prognosis and often require surgical treatment. Antibiotics must be completed for the prescribed duration according to the doctor's instructions.

Checklist Before an Outpatient Visit (Including Items to Bring and Example Questions)

• Items to bring / information to organize in advance:
  • A list of all currently used medications (including prescriptions, OTC drugs, and supplements) and the times they are taken
  • Records of allergies (especially to antibiotics, penicillin, etc.)
  • Medical history: whether a prosthetic valve has been implanted, history of heart surgery or congenital heart disease, and whether endocarditis has occurred in the past
  • A record of recent fever or symptoms suggesting infection (onset, temperature changes, and accompanying symptoms)
  • A history of recent dental or surgical procedures or catheter insertion
  • Bring previous test results if available (echocardiography reports, blood culture results, and recent blood tests)
• Key information to tell the healthcare provider first during the outpatient visit: Whether you are taking antibiotics (recent use may affect blood culture results), whether prosthetic material or a prosthetic valve is present, and any recent hospitalization or surgery
• Simple self-records that can be made for the outpatient visit: Fever records (temperature by time of day), and whether shortness of breath, chest pain, or neurological symptoms (new paralysis or speech difficulties) have occurred and when
• Example questions to use during the outpatient visit (to check yourself before the visit or present to the healthcare provider):
  • Whether there are recent blood culture or echocardiography results
  • Clearly communicate allergy information (especially penicillin)

Examples of General Questions to Ask the Doctor

• "What organism caused my infection (has it been identified), and which antibiotics do you recommend?"
• "Which antibiotic should I receive, and for how long should it be administered intravenously (or taken orally)?"
• "Is this a situation that requires surgery (such as valve replacement)? If so, what would be the expected timing and level of risk?"
• "What are the chances of recurrence and the prognosis? How long is hospitalization expected to last?"
• "What should I be careful about in daily life (exercise, work, and dental treatment)?"
• "I have an antibiotic allergy (or a history of infection with a resistant organism); what alternatives are available?"

Examples of Disease-Specific Questions

• If you have a prosthetic valve: "If this is a prosthetic-valve infection, is conservative treatment possible, and what are the criteria for deciding when to consider valve replacement surgery?"
• If you recently underwent a dental procedure: "How do you assess its relationship to the dental procedure? What preventive measures should I take for future dental procedures?"