Infective Endo, Myo, Pericarditis - Stillwell

Question 1

what is the standard treatment for endocarditis prophylaxis?

Answer 1

-oral dose amoxycillin

Question 2

what is the 4th most common life-threatening infection in humans?

Answer 2

-infective endocarditis**

Question 3

infective endocarditis

Answer 3

• inflammatory process of endocardium damaging heart valves
• form vegetations* –> can dislodge forming septic emboli
• MV > AV > TV > PV**

causes

• strep viridans (most common) –> previously damaged valves
• Staph in IV drug users
• Staph epidermidis in prosthetics
• Strep bovis in colorectal cancer

-see splinter hemorrhages, Janeway lesions, Osler nodes, subconjunctival/palatal/skin petechiae, Roth spots retina, splenomegaly**

signs/symptoms

• fever that does not go away in a few days
• start having back/abdominal pain
• worsened heart murmur
• Carvallo’s sign with tricuspid regurge
• always draw 3 sets of blood cultures every 12 hr. if suspected (check cultures every 48 hr.)
• bacteriocidal drugs work better than bacteriostatic drugs** for MRSA and MSSA

Question 4

what valve is most affected in IV drug users?**

Answer 4

-tricuspid valve**

Question 5

Noninfective endocarditis*

Answer 5

• nonbacterial thrombotic endocarditis –> hypercoaguable states
• associated with SLE** and antiphospholid syndrome –> form circulating immune complexes causing vegetations on heart valves (Libman Sacks lesions***)
• do not damage valve much, problem is the emboli*
• MV > AV > TV > PV
• cannot differentiate infective endocarditis on ECHO alone

Question 6

HACEK organisms**

Answer 6

1. Haemophilus aphrophilus
2. actinobacillus (aggregatibacter)
3. Cardiobacterium
4. Eikenella
5. Kingella

Question 7

subacute infective endocarditis

Answer 7

• strep viridans
• also strep bovis/gallolyticus

-can see clubbing in fingers/toes

Question 8

culture negative infective endocarditis*

Answer 8

1. Q fever** (coxiella burnetii)
2. Bartonella**
3. HACEK organisms
4. Tropheryma whipplei (whipple’s disease)

Question 9

most common cause of infective myocarditis

Answer 9

-viruses*

Question 10

most common cause of infective pericarditis

Answer 10

• viruses**
• coxsackievirus most common*** (also echovirus)

-in noninfective pericarditis –> Dressler syndrome* associated

• in constrictive (thickened) pericarditis –> can be caused by TB*
• TB may cause pericardial effusion but will never see on stain (need biopsy)**

-in purulent/bacterial pericarditis –> Staph aureus

Question 11

Lumierre syndrome**

Answer 11

-seen in septic thrombophlebitis*

• Fusobacterium*** enter the internal jugular vein forming a clot
• risk of IV injection site infection
• the anaerobe can lead to an air pocket on CT

-diagnosis = clot + bacteremia

Question 12

mycotic aneurysm

Answer 12

• BACTERIAL (not fungal) infection of vasa vasorum vessels –> aneurysm
• salmonella is common cause* (sometimes staph aureus, syphilis, and TB)*

-can break causing embolism and hemorrhage –> stroke

Question 13

atrial myxoma**

Answer 13

• benign tumors usually in LA**
• can run high fever even when not infected due to IL-6 release*
• may have anemia with elevated ESR/CRP/WBC
• can be secondarily infected with staph or strep

Question 14

strep gallolyticus/bovis**

Answer 14

• can have endocarditis that is associated with COLON cancer and polyps***
• do colonoscopy

Question 15

most common cause of death with infective myocarditis?***

Answer 15

• CMV**
• myocarditis also caused by coxsackievirus, adenovirus, enteroviruses, echovirus
• may see Chaga’s disease if caused by Trypanosoma cruzi parasite