Endocarditis Overview

Endocarditis

• What: Inflammation of the inner lining of the heart and valves. Infective endocarditis (IE) is more common than non-infective, which involves the formation of sterile platelet and fibrin thrombi.
• Cause (Infective): Bacterial (e.g., staph, strep viridans, strep pneumo, HACEK organisms, fungi), often following damage to the endothelium (inner lining).
• Cause (Non-Infective): Rheumatic endocarditis, impacting mitral valves more than aortic, occurs due to damage to endothelium which allows for platelet and fibrin deposition and bacteria invasion.
• Classifying Endocarditis:
  • Acute (sudden onset, often staph) vs. Subacute (gradual onset, often strep viridans)
  • Native valve (community acquired, IV drug use) vs. Prosthetic valve
  • Left-sided vs. Right-sided (IV drug use)
• Clinical Signs/Symptoms (more common in IE): Fever, night sweats, fatigue, anorexia, weight loss, myalgias/arthralgias, splinter hemorrhages, Osler nodes, Janeway lesions, Roth spots, new or changing murmurs (mitral regurgitation, tricuspid regurgitation).
• Diagnosis:
  • Echocardiography (TTE initial, TEE for negative TTE): assesses heart valves and structures.
  • Blood cultures: 3 sets from different sites prior to antibiotic treatment.
  • Inflammatory markers (ESR, CRP): elevated.
  • Other tests: ECG, CXR, CT, MRI (to rule out other causes or evaluate for complications).
• Treatment (Infective): Empiric antibiotics (e.g., vancomycin + gent, ceftriaxone; nafcillin + gent) followed by a longer course of antibiotics (4 to 6 weeks). Consult ID, cardiology, CT surgery. Native valve patients: vancomycin + gentamicin OR ceftriaxone.prosthetic valve patients: Vancomycin, gent, rifampin. Ongoing blood cultures monitored.
• Risks: Patients with native valve endocarditis, prosthetic valves or are IV drug users require prophylactic antibiotics before dental or other invasive procedures (e.g., amikacin, ceph, or clinda). A history of rheumatic heart disease, congenital heart disease, prior infection, and poor dentition place individuals at higher risk.
• Complications: Cardiac complications (perivalvular infections, valve insufficiency, valve rupture, HF, endocarditis-related pericarditis), renal complications (glomerulonephritis, antibiotic-induced nephrotoxicity), and metastatic infections, are potential consequences.

Pericarditis

• What: Inflammation of the pericardium (the double-layered sac surrounding the heart).
• Cause: Idiopathic, viral infection (coxsackievirus B), bacterial infections, cardiovascular conditions (e.g., post-MI Dressler syndrome), cancers, medications, or autoimmune diseases.
• Clinical Signs/Symptoms (Acute): Severe, sharp, pleuritic chest pain that may radiate to neck, shoulder, or arm; worsens when lying supine, improving when leaning forward; potential for dyspnea, neck vein distention, pericardial friction rub (heard best on expiration while leaning forward).
• Clinical Signs/Symptoms (Chronic): May be less severe or absent, could cause dyspnea (SOB).
• Diagnosis: EKG (ST-segment elevation, PR depression, and often diffuse ST segment elevation is acute; PR depression in chronic); Echocardiogram (identify any effusion/edema).
• Treatment (Viral/Idiopathic): NSAIDs or high-dose aspirin (7 to 14 days). Potential for colchicine to also be used to decrease recurrence. Steroids if no improvement with NSAIDs.
• Complications: Cardiac tamponade (fluid buildup compresses the heart), pericardial effusion, constrictive pericarditis, which can cause right-sided heart failure symptoms.

Pericardial Effusion and Cardiac Tamponade

• What: Pericardial effusion is the accumulation of fluid within the pericardial sac; Cardiac tamponade is a serious consequence of rapid fluid accumulation that impairs cardiac filling.
• Causes: Viral infections, bacterial infections, malignancy, trauma, medication effects.
• Signs/Symptoms (with Tamponade): Dyspnea, cough, chest pain, lightheadedness, syncope, palpitations, hoarseness, fatigue. The triad of hypotension, muffled heart sounds, and weak pulse is significant.
• Signs/Symptoms (without Tamponade): Often asymptomatic, symptoms relate to the underlying cause.
• Diagnosis: EKG, CXR, echocardiogram (TEE preferred), blood tests (important to evaluate for ESR, CRP, and CBC)
• Treatment: Treatment depends on the underlying cause and stability: may include administering O2, IV fluids, pericardiocentesis (for large effusions), surgical intervention (for certain cases) if necessary.

Myocarditis

• What: Inflammation of the myocardium (heart muscle).
• Causes: Idiopathic, Viral (e.g., Coxsackie B virus, other viruses), bacterial, protozoal, fungal infections, immune-mediated disorders (e.g., rheumatologic conditions), medications, and environmental factors (e.g., black widow venom).
• Signs/Symptoms: Fever, chest pain, dyspnea, orthopnea, loss of appetite, fatigue, palpitations, and heart failure signs, JVD/edema, murmurs (MR/TR).
• Diagnosis: EKG, CXR, echocardiogram, Endomyocardial biopsy (gold standard). Blood tests may be done to check other conditions. Cardiac MRI.
• Treatment: Supportive treatment focused on heart failure management (e.g., diuretics, ACE inhibitors, beta-blockers), managing arrhythmias, and addressing underlying causes.