11 17 2014 Endocarditis

Question 1

Mecahism by which injury leads to valve vegetation formation

Answer 1

Endothelial injury usually occurs due to turbulent blood flow resulting from a pre-existing valvular disease

Endothelial injury may also occur due to foreign material within circulation– venous catheters/ prosthetic heart valves

Once endothelial surface is exposed, platelets adhere to collaged and initiate the formation of a sterile thrombus – Nonbacterial thrombotic endocarditis (NBTE)

Question 2

List the common pathogens that cause infection for endocarditis

Answer 2

1. Staphylococci Aureus ( more virulent)
2. Streptococci ( specifically Viridans)
3. HACEK bacteria: Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella)
   - oral cavity
4. Acute Rheumatic Fever : Group A beta-hemolytic stretpococcal infection (GABH) – starts as pharyngitis

Note that in a rural area with not IV drug users, Strep Viradans infection is greater than staph aureus

Question 3

Mechanism for infections endocarditis

Answer 3

Formation of thrombus ( NBTE – nonbacterial thrombotic endocarditis) is caused by endothelial injury that caused platelets to aggregate and form a sterile thrombus through fibrin deposition.

Fibrin-platelet deposit = surface of adherence by bacteria.

Fibrin then covers organisms and protects them from host defenses by inhibiting chemotadis and migraiton of phagocytes

Question 4

Acute Endocarditis Clinical Presentation:

Answer 4

Acute onset of high-grade fever and shaking chills

Rapid onset of Cardiac Heart failure due to structural damage

  - rapid valve failure

HIghly virulent organism attacking a normal valve

* Cerebellar complications – large mobile and on mitral valve

High morbidity and mortality even with appropriate therapy/surgery

Question 5

Subacute endocarditis Clinical Presentation

Answer 5

Low grade fever with non-specific fatigue, anorexia, weight loss, and “flu-like” symptoms

* fever may be absent in elderly

Less virulent organims but also happens due to an already abnormal valve

* Aortic valve (most common), Mitral valve (2nd common)

Tricuspid Valve ( tricuspid regurgitation) – IV drug users

Question 6

Endocarditis is assumed to be correct diagnosis (until proven otherwise) when what two criteria are present?

Answer 6

New regurgitant murmur + Recurrent/ unremitting fever

Question 7

Clinical Features of infectious Endocarditis – physical findings

Answer 7

1. Osler nodes: painful fingertip nodules
2. Janeway Lesion : painless palm or sole erythematous lesion
3. Splinter Hemorrhages: petechia nail bed
4. Roth Spots: Retinal hemorrhage
5. 90% of patients have a murmur

Question 8

Rheumatic Fever Clinical features:

1. who does it affect?
2. when does it present?

Answer 8

Children

2-3 weeks after streptococcal infection

Question 9

Rheumatic Fever major criteria:

Answer 9

JONES

J- Joints : polyarthritis : swelling, redness, warmth, tenderness

O– carditis – aortic or mitral regurgitation

N–Nodules (subcutaneous)

E– Erythema marginatum

S– Sydenham chorea: uncoordinated involuntary purposeless movements

• patient cannot maintain clenched fists

Question 10

Rheumatic fever minor criteria:

Answer 10

CAFE PAL

C– CRP increased

A– Arthralgia

F– Fever

E– Elevated ESR

P – Prolonged PR interval

L– Leukocytosis

Question 11

What are the requirements needed to diagnose RF?

Answer 11

2 major criteria

OR

1 major criteria and 2 Minor criterias

* throat culture and take blood titers of antibody. ** GO WITH BLOOD TITERS**

Recall that patients come 2-3 weeks after suffering from RF – may no longer be in throat