Basics
Description
An inflammation of the endothelial surface of the heart
- Various cardiac structures may be involved:
- Native heart valves (most common)
- Prosthetic valves
- Interventricular septum
- Chordae tendineae
- Mural endocardium
- Intracardiac devices
- Characterized by a vegetation (a thrombus with superimposed microorganisms)
- Bacterial colonization of the initially sterile vegetation composed of fibrin and platelets
- Bacterial growth enlarges the vegetation, further impeding blood flow and inciting inflammation.
- Propagation of the infection through systemic emboli
- Almost always secondary to bacterial infection
- Rare noninfectious causes
- Nonbacterial thrombic endocarditis or marantic endocarditis
- Often due to a hypercoagulable state
- Small sterile vegetations
- Libman-Sacks endocarditis
- Complications of lupus erythematosus
- Due to the deposition of immune complexes that cause an inflammatory reaction
- Small vegetations
Epidemiology
- More common in men (ratios from 3.2 to 9.1)
- M: 8.6-12.7 cases/100,000 person-yr
- F: 1.4-6.7 cases/100,000 person-yr
- Risk factors:
- Older patients
- Poor dental hygiene
- Comorbidities
- Rheumatic heart disease
- Prosthetic valve
- Hemodialysis
- Diabetes
- IV drug abuse (IVDA):
- Greater risk than rheumatic heart disease or prosthetic valves
- Predilection for right-sided heart valves
- Septic embolization
- Cerebral complications
- Cerebral embolism
- Intracranial hemorrhage
- Cerebral abscess
- Extracerebral embolic events
- Pulmonary
- Splenic
- Renal
- Mycotic aneurysms (aorta, renal artery, splenic artery, hepatic artery, mesenteric arteries, etc.)
- Hepatic
- Coronary
- Risk factor for recurrent endocarditis:
- Structural heart disease serves as common vegetative site due to altered intracardiac flow:
- Mitral valve prolapse
- Aortic valve dysfunction
- Congenital heart disorders in the pediatric populations:
- Tetralogy of Fallot
- Aortic stenosis
- Patent ductus arteriosus
- Ventricular septal defects
- Aortic coarctation
- Prosthetic valves
- Indwelling catheters
- Any mechanical device may serve as a portal of entry or attachment for microorganisms.
Etiology
- Major categories:
- Bacterial endocarditis
- Prosthetic valve endocarditis
- Nonbacterial thrombotic endocarditis:
- Malignancy
- Uremia
- Burns
- Systemic lupus erythematosus
- Common organisms:
- Staphylococcus aureus (most common pathogen):
- Seen in all populations, especially IVDA and toxic illness
- Sometimes metastatic
- Streptococcus viridans:
- Found in oropharynx, common agent in native valve endocarditis
- Streptococcus bovis:
- Common association with colonic polyps or GI malignancy
- Streptococcus pneumoniae:
- Causes rapid valvular destruction, abscess, and CHF
- Risk factor: Alcoholism
- Staphylococcus epidermidis
- Enterococci:
- Seen in young women and old men following instrumentation or infection
- Candida and Aspergillus:
- Found in IVDA, prosthetic valves, or immunocompromised patients
- HACEK (Haemophilus sp.)
- Culture-negative endocarditis (Q fever, psittacosis, Bartonella, brucellosis)
Diagnosis
Signs and Symptoms
- Fever:
- Present in 86% of patients
- May be absent in certain settings:
- Elderly
- CHF
- Severe debility
- Chronic renal failure
- Flulike illness
- Chills
- Sweats
- Rigors
- Malaise
- Head, eyes, ears, nose, and throat:
- Retinal hemorrhages or Roth spots
- Respiratory:
- Dyspnea
- Cough
- Heart failure
- Cardiac:
- A new or changing murmur in 80-85% of patients
- Abdominal:
- Abdominal or back pain
- Splenomegaly (15-50%)
- Extremities:
- Myalgias
- Arthralgias
- Digital clubbing
- Neurologic:
- Altered mental status
- Septic embolization (stroke or mycotic aneurysm)
- Skin:
- Cutaneous vasculitic lesions:
- Mucosal and conjunctival petechiae
- Splinter hemorrhages
- Osler nodes: Erythematous, painful tender nodules
- Janeway lesions: Erythematous or hemorrhagic, macular or nodular lesions, a few millimeters in diameter on the hands and feet
History
- Fever duration and pattern
- Risk factors:
- Prior cardiac disease
- Source of bacteremia:
- Indwelling intravascular catheters
- IV drug use
- Poor dental hygiene
Physical Exam
- Heart and lung exam:
- New cardiac regurgitant murmur
- Heart failure
- Assess for splenomegaly.
- Assess for septic emboli:
- Fundi, skin, nail beds
- Careful neurologic exam for small focal deficits
Essential Workup
- Identify risk factors for endocarditis in patients with fever of unknown etiology.
- Blood cultures
- ECG is needed to confirm the diagnosis.
Diagnosis Tests & Interpretation
Lab
- CBC:
- Anemia (sometimes hemolytic)
- Leukocytosis (with granulocytosis and bandemia)
- Blood cultures:
- Multiple sets (3 sets over a time period) should be obtained before antibiotic administration:
- 5-10% with endocarditis have false-negative cultures
- Consider culture of catheter device
- Elevated sedimentation rate and C-reactive protein (lacks specificity)
- Urinalysis:
Imaging
- CXR:
- CHF
- Septic pulmonic emboli, which may be seen in right-sided endocarditis
- EKG
- Arrhythmia, new heart block
- Echocardiogram
- Acute valvular pathology
- Abscess
- Vegetations
- Transesophageal echo provides greater sensitivity.
- CT scan
- May provide comprehensive information and valvular abnormalities
Differential Diagnosis
- Rheumatic fever
- Atrial myxoma
- Acute pericarditis
- MI
- Aortic dissection with regurgitant valve
- Thrombotic thrombocytopenic purpura
- Systemic lupus erythematosus
- Occult neoplasm with metastasis
- Septicemia
- Cotton fever
Treatment
Initial Stabilization/Therapy
- Monitor for signs of heart failure.
- Operative repair if:
- Severe valvular dysfunction causing failure
- Unstable prosthesis
- Perivalvular extension with intracardiac abscess
- Antimicrobial therapy failure
- Large or fungal vegetations
- Antibiotic therapy:
- IV, bactericidal, and empiric, pending culture results
- Native valve or congenital abnormality:
- Penicillin G + nafcillin + gentamicin
- Vancomycin + gentamicin
- Prosthetic valve or history of IVDA:
- Vancomycin + gentamicin + rifampin
- Nafcillin + gentamicin + rifampin (if methicillin-resistant S. aureus [MRSA] is not suspected)
- If MRSA vancomycin failure/intolerant consider daptomycin or quinupristin-dalfopristin
- Vancomycin resistant
- Enterococcus faecium consider quinupristin-dalfopristin
- Enterococcal: Penicillin G + gentamicin; vancomycin + gentamicin
- Enterococcal (gentamicin resistant): Penicillin G + streptomycin
- Fungal:
- HACEK:
Medication
- Amphotericin B:
- Test dose 0.1 mg/kg up to 1 mg slow IV
- Wait 2-4 hr.
- If tolerated, begin 0.25 mg/kg IV and advance to 0.6 mg/kg IV QID
- Ceftriaxone: 2 g/d IV (peds: 100 mg/kg/24h)
- Daptomycin: 4 mg/kg/d U IV
- Gentamicin: 1 mg/kg IV q8h (peds: 3 mg/kg/24h in 3 equally div. doses)
- Nafcillin: 2 g IV q4h
- Penicillin G: 4 million IU IV q4h (peds: 300,000 U/kg/d div. into 4 equal doses)
- Quinupristin-dalfopristin: 7.5 mg/kg IV q8h (peds: 7.5 mg/kg/12h)
- Rifampin: 600 mg PO QID
- Streptomycin: 15 mg/kg/24h IV/IM in 2 equally div. doses (peds: 20 mg/kg/24h IV in 2 equally div. doses)
- Vancomycin: 15 mg/kg IV q12h (peds: 40 mg/kg/24h in 2-3 equally div. doses)
Follow-Up
Disposition
Admission Criteria
- Patients with risk factors who exhibit pathologic criteria or clinical findings
- All IV drug users with fever
- Admit patients with cardiovascular instability to an intensive care unit/monitored setting.
Discharge Criteria
None
Follow-Up Recommendations
- Expected course:
- Most patients will defervesce within 1 wk.
- Complications:
- Cardiac: CHF, valve abscess, pericarditis, fistula
- Neurologic: Embolic stroke, abscess, hemorrhage
- Embolization: CNS, pulmonary, ischemic extremities
- Mycotic aneurysms: Cerebral or systemic
- Renal: Infarction, nephritis, abscess
- Metastatic abscess: Kidney, spleen, tissue
Pearls and Pitfalls
- Fever, new or changing murmur
- 50% of cases occur in patients with no known history of valve disease
- Recent health care exposure/device consider as risk factor
- Common complications; watch for stroke, embolization, heart failure, intracardiac abscess
- Admit IV drug abusers presenting with fever to rule out endocarditis.
- Empiric therapy for acutely ill after 2-3 sets of blood cultures from separate venipuncture sites.
Additional Reading
- Chen RS, Bivens MJ, Grossman SA. Diagnosis and management of valvular heart disease in emergency medicine. Emerg Med Clin North Am. 2011;29(4):801-810.
- Hoen B, Duval X. Clinical practice. Infective endocarditis. N Engl J Med. 2013;368(15):1425-1433.
- Keynan Y, Rubinstein E. Pathophysiology of infective endocarditis. Curr Infect Dis Rep. 2013;15(4):342-346.
- Murdoch DR, Corey GR, Hoen B, et al. Clinical presentation, etiology, and outcome of infective endocarditis in the 21st century: The International Collaboration on Endocarditis-Prospective Cohort Study. Arch Intern Med. 2009;169(5):463-473.
- Selton-Suty C, C ©lard M, Le Moing V, et al. Preeminence of Staphylococcus aureus in infective endocarditis: A 1-year population-based survey. Clin Infect Dis. 2012;54(9):1230-1239.
Codes
ICD9
- 421.0 Acute and subacute bacterial endocarditis
- 424.90 Endocarditis, valve unspecified, unspecified cause
- 996.61 Infection and inflammatory reaction due to cardiac device, implant, and graft
- 424.91 Endocarditis in diseases classified elsewhere
- 424.99 Other endocarditis, valve unspecified
ICD10
- I33.0 Acute and subacute infective endocarditis
- I38 Endocarditis, valve unspecified
- T82.6XXA Infect/inflm reaction due to cardiac valve prosthesis, init
- I39 Endocarditis and heart valve disord in dis classd elswhr
- M32.11 Endocarditis in systemic lupus erythematosus
SNOMED
- 56819008 Endocarditis (disorder)
- 301183007 Bacterial endocarditis (disorder)
- 233853009 Prosthetic valve endocarditis (disorder)
- 57181007 Nonbacterial thrombotic endocarditis (disorder)
- 459057007 Viral endocarditis (disorder)
- 54072008 Nonbacterial verrucal endocardiosis (disorder)
- 73028002 staphylococcal endocarditis (disorder)
- 86100009 Vegetative endocarditis
- 86348002 Mycotic endocarditis (disorder)
- 89736004 Valvular endocarditis