Infectious endocarditits

Question 1

Why do patients have splenomegaly?

Answer 1

Answer will be in class

Question 2

What is the most common organism that causes infectious endocarditis? What type of IE does it cause?

Answer 2

Staphylococcus aureus

- causes Acute Infectious endocarditis

Question 3

The uncommon clinical manifestations of IE?

Answer 3

1. Janeway lesions - nontender erythematous macules on the palms and soles (microabscesses) (more common in acute IE)
2. Osler nodes - tender subcutaneous purple nodules mostly on the pads of the fingers and toes (Immune-mediated)
3. Roth Spots - exudative, edematous hemorrhagic lesions of the retina with pale centers (immune-mediated)

Question 4

Neurologic complications of IE?

Answer 4

1. Embolic stroke
2. Intracerebral hemorrhage
3. Brain abscesses

Question 5

Characteristics of the vegetations found in infectious endocarditis?

Answer 5

Friable, bulky lesions containing fibrin, inflammatory cells, bacteria, and other organisms

• single or multiple
• can erode into myocardium, developing abscesses
• prone to embolization
• abscesses frequently develop where they lodge, leading to septic infarcts

Question 6

Clinical presentation of Acute endocarditis?

Answer 6

Acute/ rapid onset of:

1. Fever!
2. Cardiac murmers
3. Splenomegaly
4. Petchiae
5. Splinter hemorrhages

• chills, weakness, malaise, anorexia, weight loss
• headaches, myalgias, arthralgias, night sweats, dyspnea, cough, pleuritic pain

Question 7

When should IE be suspected?

Answer 7

In patients with:

- Fever and relevant cardiac risk factors or noncardiac risk factors (IVDU or recent dental procedure)

Question 8

Acute vs. subacute Infectious endocarditis

Answer 8

Acute: infection of a previously NORMAL heart valve by a HIGHLY virulent organism
- produces necrotizing and destructive lesions

Subacute: insidious infection of DEFORMED valves by organism with LESS virulence
- less destruction

Question 9

Pathological criteria used for definite endocarditis according to the Modified Duke Criteria?

Answer 9

1. Path Lesion: Vegitation or intracardiac abscess demonstrating active endocarditis on histology
2. Microorganisms: demonstrated by culture or histology of a vegatation or intracardiac abscess

Question 10

What is infectious endocarditis?

Answer 10

A microbial infection of the heart valves or mural endocardium

• leads to vegitations composed of thrombotic debris and organism
• associated with destruction of underlying cardiac tissue

Question 11

Diagnosis of IE is based on?

Answer 11

1. Clinical manifestations
2. Blood cultures
3. Echocardiography

• other hints: Elevated ESR, CRP, anemia, positive rheumatoid factor, UA with hematuria, proteinuria or pyuria

Question 12

Special population etiology:

Organisms that cause IE in those with colon cancer?

Answer 12

Streptococcus gallolyticus (formerly S. bovis)

Question 13

Tx of IE?

Answer 13

Emperically tx with Vancomycin (assuming gram-positive)

• in rare case that it is a gram-negative organism, we can adjust tx

Question 14

Etiology:

Organisms that cause IE?

Answer 14

1. Staph. Aureus
2. Streptococcus Viridans
3. Enterococcus species
4. Staph epidermidis
5. HACEK organisms (Gram-Neg!)
6. Fungi
7. Bartonella or Coxiella (culture-neg)

Question 15

Clinical presentation of subacute endocarditis?

Answer 15

Gradual onset of:

1. low-grade fever
2. Cardiac murmers
3. Splenomegaly
4. Petchiae
5. Splinter hemorrhages

night sweats, weight loss, anorexia and fatigue

Question 16

Prognosis for IE?

Answer 16

Not good

~25% die in hospital

Question 17

Unique features of HACEK organisms?

Answer 17

• Gram-negative

- more difficult to culture

Question 18

Clinical Criteria used for definite endocarditis according to the Modified Duke Criteria?

Answer 18

1. Two major clinical criteria = Dx
2. One major and 3 minor = Dx
3. Five minor = Dx

Question 19

Special population etiology:

Organisms that cause IE in IV drug users?

Answer 19

1. S. Aureus!
2. Pseudomonas
3. Candida species

-in that order

Question 20

Risk factors for IE?

Answer 20

• IV drug use
• Males
• Age > 60
• Poor dentition
• Preexisting heart disease
• prosthetic heart disease
• hx of IE
• other foreign devices
• chronic hemodialysis
• HIV

Question 21

Special population etiology:

Organisms that cause IE in PTs w/ prosthetic valve?

Answer 21

S. epidermidis

- Able to form a biofilm on the prosthesis

Question 22

Why is streptoccocus gallolyticus associated with colon cancer?

Answer 22

Answer will be in class

Question 23

What needs to be obtained before tx of IE with antibiotics?

Answer 23

At least 3 sets of blood cultures from separate sites

Question 24

other non-specific complications of IE?

Answer 24

1. Septic emboli (infarcts of kidneys, spleen, etc)
   - pumlonary emboli w/ right-sided IE from IVDU
2. Metastatic infection (vertebral osteomyelitis, septic arthritis, psoas abscess
3. Systemic immune reaction

Question 25

Why do patients with IE become anemic

Answer 25

Answer will be in class

Question 26

Cardiac complications of IE?

Answer 26

1. Valve insufficency
2. Heart failure
3. Chordae rupture
4. Suppurative (pus) pericarditis

Question 27

Most common sites of infection seen in IE?

Answer 27

1. Aortic and MITRAL valves

- Tricuspid valve for IV drug users (Right heart)

Question 28

What type of bacterial typically cause endocarditis; Gram-neg or Gram-pos?

Answer 28

Gram positive

- they are more capable of adhering to the heart valves