Endocarditis - Overview and Differential Diagnosis Framework



Who?

Infectious:

• Pre-existing valvular disease

• Prosthetic valve

• Congenital heart disease

• IV substance use

• IV catheter

• Recent dental procedure

• Cardiac implantable electronic devices (CIED)

Non-Infectious (NTBE):

• Malignancy (Marantic, verrucous) - Lung, Pancreas, Gastric & Ovarian CA, involves aortic and mitral regurgitation

• Autoimmune (SLE Libman Sacks)

• Atrial myxoma

• Hypercoagulable (APLAS)



Microbiology:

Blood cultures are positive in 90% of IE cases

Culture Positive:

• Acute: S. Aureus, S. Epidermidis, S. Pyogenes, Enterococci

• Subacute: S. Viridans (Sanguinis, Mitis, Oralis, Mutans), S. Bovis, S. gallolyticus, HACEK, H. Parainfluenzae, H. Influenza

• Prosthetic Valve Endocarditis: s. aureus, Coagulase-negative staphylococci



Culture Negative:

• Bartonella

• Brucella

• Coxiella Burnetii

• Streptobacillus Moniliformis

• Tropheryma Whipplei

• Aspergillus

• Cryptococcus, Histoplasma



What?

Generalized: Chills, night sweats, fever, Malaise, fatigue, weight loss, Myalgias

Cardiac:

• New cardiac murmur

• Valvular insufficiency

• New-onset heart failure

• Dyspnea

Vascular:

• Systemic emboli: Cerebral > Splenic, Pulmonary

• Janeway lesions

• Mycotic aneurysm

• Splinter hemorrhages

• Petechiae

Immunologic:

• Osler nodes

• Roth’s spots

• Glomerulonephritis

DDX:

• Rheumatic valvular disease

• Degenerative valvular disease

• Vasculitis

• Cholesterol emboli syndrome

• Fibroelastoma

• Lamb’s excrescences

• Paradoxical emboli via ASD

• Metastatic disease and tumor embolism



Septic emboli cause injury by:

• Early embolic/ischemic insult due to vascular occlusion that may lead to infarction

• Infectious insult that leads to inflammation and possible abscess formation

• Other vegetations can also embolize: Marantic (NTBE)



Diagnosis:

• Blood cultures

• 2D Echo TTE

	○ TTE nondiagnostic + ↑Suspicion → TEE

• Duke Criteria

• ↑ ESR, CRP

• EKG: Conduction abnormalities (suggests perivalvular abscess)

• Leukocytosis, anemia, and hematuria, + RF



Treatment

• IV antibiotics

• Surgery

• Marantic: Treat underlying cause + Systemic anticoagulation



Pearls?

• Left sided > Right sided

• IV substance use: R > L Tricuspid

• Marantic: Emboli > Regurgitation

• Colon CA: S. Bovis, gallolyticus, clostridium septicum

• S. Viridans



Surgery:

• Valvular dysfunction → symptomatic heart failure

• Left sided IE: Heart block, annular or aortic abscess, or destructive lesion

• Complications: Abscess, destructive penetrating lesions, heart block

• Persistent bacteremia/fevers > than 5 to 7 days after onset of appropriate antimicrobial therapy

• >10-mm left sided vegetations to prevent emboli

• S. aureus prosthetic valve endocarditis



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