Endocarditis

Question 1

A 53 y/o homeless, alcoholic, male was admitted with a right hemiparesis. He had been seen in the ER two weeks ago and again one week ago after being picked up in the street by the police. He was found to have a fever of 38.3 degrees centigrade (101F) on both occasions. He was also found to be covered by body lice in each instance. A total of 6 blood cultures had been negative. Physical exam upon admission revealed a temperature of 39 degrees C, a diastolic descrendo murmur at Erbs area, and negative repeat blood cultures.

Answer 1

Fever of unidentified origin

Question 2

Rule of threes

Answer 2

Three office visits, 3 weeks of fever, 38.3 C

Negative workup

Fever of unidentified origin

Question 3

Primary causes of FUO

Answer 3

**Infection (TB and endocarditis, occult abscess)
Cancer (lymphoma, leukemia)
Autoimmune/Connective Tissue Disease (Still’s disease, SLE, cryoglobulinemia, PAN)
Miscellaneous (sarcoid, FMF, Whipples, thyroiditis)
Undetermined

Question 4

What causes the fever

Answer 4

IL1, IL6, TNFα -> produce PGE2 via endothelial and glial receptor stimulation -> stimulate hypothalamus to produce fever

Question 5

Modified Duke criteria for endocarditis

Answer 5

1) Two major out of three criteria of:
Two positive blood cultures
Echo evidence of endocardial involvement
New regurgitant murmur

2) One major and 3 minor or 5 minor, with minor being:
Predisposing condition
Fever of 38 degrees or higher
Vascular emboli (the actual bug): Janeway lesion, splinter hemorrhages (nails), mycotic aneurysm, conjunctival or cutaneous hemorrhage, PE, stroke, MI, etc.
Immunologic phenomena (IC deposition): Osler node, Roth spots, RF, GN (hematuria and proteinuria)

Question 6

Janeway lesion

Answer 6

Flat, painless, septic microemboli

Hands and feet

Question 7

Osler node

Answer 7

Painful and vasculitic

Can form anywhere

Question 8

Roth spots

Answer 8

Retinal hemorrhages

Question 9

Set up for infective endocarditis

Answer 9

Regurgitant valves, bicuspid valves, rheumatic valves, calcific valves, MVP, PDA, Coarctation, VSD

Question 10

Acute endocarditis with virulent organisms

Answer 10

Valvular regurgitation, high fever, early embolization

Question 11

Native valve endocarditis

Answer 11

Transient bacteremia as from brushing teeth to IV devices

Bacteria land on troubled valve

Question 12

Bacteria most likely to cause native valve endocarditis

Answer 12

Staphylococcus

May also be Strep viridans or bovis, group D streptococcus or HACEK

Question 13

IV drug users get endocarditis from

Answer 13

Staph

Then enterococcus and strep

Question 14

Valve most effected in IV drug users

Answer 14

Tricispid valve

Question 15

Prosthetic valve endocarditis (early and late)

Answer 15

Early - coagulase + and – staphylococcus

Late - streptococcusor or staph

Question 16

What if culture is negative

Answer 16

1) Fungi
2) Need special media - Legionella, Bartonella, and Abiotrophia
3) No growth on artificial media - Tropheryma whipelli, Q fever or psittacosis pathogens
4) Slow growing with prolonged incubation - Brucella, anaerobes, HACEK

Eikenella corrodens
Aggregatibacter (Haemophilus) aphrophilus, Aggregatibacter (Acintobacillus) actinomcetemcomitans, Cardiobacterium hominis, Kingella

Question 17

How to diagnose endocarditis

Answer 17

Draw 3 cultures one hour apart
2 positives
3 if skin contamination - coag neg staph

Question 18

A patient, who works for a computer company and has a history of a prosthetic aortic valve, has had a low grade fever, a new diastolic murmur at the aortic area and negative blood cultures for the past three months. Cardiac ECHO has shown no vegetations, but an abdominal aortic aneurysm was accidentally found. He has had a cat for 10 years. He is positive for RF.

Answer 18

Endocarditis from Coxiella burnetii

Question 19

Complications of endocarditis

Answer 19

Heart block, CHF, emboli, mycotic aneurysms, myocardial abscess

Question 20

Specific treatment of endocarditis

Answer 20

Acute Coxiella infection - Doxycycline 
Chronic infection - Doxycycline
Bartonella hensalae or quintana - Doxycline
Streptococcus endocarditis - Penicillin
Enterococcal endocarditis - Penicillin plus gentamicin (risk of renal failure)
Staphylococcus endocarditis - Nafcillin 
Methicillin resistant – Vancomycin
Surgery

Question 21

Treatment of endocarditis before cultures

Answer 21

Native valve: Vancomycin

Prosthetic valve: Vancomycin, Gentamycin, Rifampin

Surgery consult, especially in prosthetic valve endocarditis

Question 22

Why do you use Rifampin?

Answer 22

It kills staph adhered to foreign material (like prosthetic valve)

Question 23

Antibacterial effect of Vancomycin

Answer 23

Interrupt cell wall synthesis

Question 24

Antibacterial effect of Gentamycin

Answer 24

Disrupt protein synthesis

Question 25

Antibacterial effect of Rifampin

Answer 25

DNA Dependent RNA Polymerase

Question 26

Streptococcus bovis

Answer 26

GI neoplasms

Question 27

Streptococcus mutans

Answer 27

Poor dentition

Question 28

Enterococci

Answer 28

Elderly with urinary problems

Question 29

HACEK

Answer 29

Prolonged incubation

Question 30

Late prosthetic valve (>2 mo)

Answer 30

Streptococcus

Question 31

IV drug users

Answer 31

Staph aureus (or epidermis)

Question 32

Alcoholics and street people

Answer 32

Bartonella

Question 33

No growth

Answer 33

Tropheryma, Q fever

Question 34

Endocarditis Prophylaxis

Answer 34

High risk cardiac populations - Previous IE, Prosthetic valves or material, and Cyanotic congenital heart disease - Tetralogy of Fallot, Eisenmenger syndrome

Only for perforating procedures of - Teeth, Lungs, and Skin

Question 35

Antibiotic before dental procedure

Answer 35

Amoxicillin 2 grams 1 hour

Question 36

A 35 y/o female presents with fever, weight loss, leukocytosis, elevated sed rate, elevated RF, and episodic pulmonary edema and syncope, especially with standing (occludes mitral valve). The patient had a recent stroke. A physical exam shows a diastolic rumble with an occasional diastolic extra sound at the mitral valve area upon standing. There is a lesion resembling an Osler node on her right great toe. This patient most likely has an:

Answer 36

Atrial Myxoma

Can present like endocarditis

Question 37

Myxoma vs endocarditis

Answer 37

Syncope true to myxoma

Question 38

Atrial myxoma

Answer 38

Seen in Carney complex of pigmented skin lesions and endocrine neoplasia. Looks like a systemic illness with emboli-usually left atrium. Diastolic tumor plop and rumble, upright CHF. Cause is related to a cAMP activated protein kinase A with activated cell proliferation (PRKAR1A gene); a multiple neoplasia syndrome.