Endocarditis

Question 1

What is endocarditis?

Answer 1

Infection of the inside of the heart

Question 2

What part of the heart is most often infected during endocarditis?

Answer 2

Almost always the valves.

Mostly left sided

Question 3

What is the prognosis of endocarditis usually?

Answer 3

Fatal if it is untreated:

In acute infections death takes less than 6 weeks)

In subacute infections death occurs between 6 weeks and 3 months

in chronic endocarditis death occurs more than 3 months after initial infection

Question 4

How common is endocarditis?

Answer 4

15 / 100000

300 - 400 cases per year in Perth

Question 5

What are the 2 things that typically cause endocarditis?

Answer 5

Valvular endothelium damage due to trauma, turbulence, or metabolic changes results in platelet-fibrin deposition on valves.

Mucous membranes or other tissues get colonized and local ecologic factors, bacteriocins, IgA protease, or bacterial adherence results in trauma, bacteremia, and damage to valve

Question 6

What disease historically caused endocarditis?

Answer 6

Rheumatic fever

Question 7

What are the risk factors for endocarditis?

Answer 7

Age (>60)

Dental disease

IVDU

Haemodyalysis

Structural heart disease/valvular heart disease

Past IE

Question 8

What bacteria are very good at attaching to heart valves?

Answer 8

Staph aureus

Question 9

What heart diseases are associated with endocarditis?

Answer 9

Rheumatic heart disease

Prosthetic heart valves

Congenital heart disease

Question 10

What bacteria are commonly associated with endocarditis?

Answer 10

Gram positive bacteria such as staph aureus, coag neg staph, and Viridans group strep

Question 11

How is infective endocarditis often treated?

Answer 11

With antibiotics

Question 12

Who get S.Aureus endocarditis most often?

Answer 12

Drug abusers

Question 13

What are the most common bacteria to cause prosethetic valve endocarditis?

Answer 13

First 12 months after surgery bacteria most common to infect prosthetic valves change. Initially during the first 3 months S.aureus and coag negative staph most commonly causes infection but by the 12th month strep and staph cause it equally and then after 12 months the strep take over as most common causes of prosthetic valve endocarditis

Question 14

What are complications of endocarditis?

Answer 14

Valve destruction causing heart failure

Intra-cardiac abscess and conduction disturbance (heart block)

Embolic MI

Metastatic abscesses (not uncommon 10 - 30%)

Mycotic aneurysms (often asymptomatic but can also rupture)

Immunological complications

Sepsis in acute IE

Question 15

How common is embolic cardiac failure?

Answer 15

Clinically apparent in 10 - 40%

Question 16

What problems can embolic complications of endocarditis result in?

Answer 16

Stroke/Limb/Viscera

Question 17

Where can metastatic abscesses form?

Answer 17

Viscera

Spine

Joints

Question 18

What are the immunological complications that can take place in infective endocarditis?

Answer 18

Seen more commonly in sub acute cases

Glomerulonephritis most significant

Immune complex deposition can trigger inflammation in surrounding areas

Question 19

What are the ways of diagnosing endocarditis?

Answer 19

Blood cultures to check for infection.

ECG (show that theres a vegetation and valve disruption)

Question 20

How are blood cultures carried out to diagnose infective endocarditis?

Answer 20

Initial 3 sets from 3 sites

3rd is 1 hour after the 1st

Occasionally serology and blood PCR for culture negative cases are used

Question 21

What can imaging show endocarditis?

Answer 21

It can reveal metastatic foci (guided by clinical picture)

Question 22

What are the Duke major criteria for endocarditis?

Answer 22

Sustained bacteremia or vegetations on the valve

Question 23

What are the Duke minor criteria for endocarditis?

Answer 23

The other symptoms that are associated with endocarditis

Question 24

How is endocarditis treated?

Answer 24

Antibiotics: Most IE are treated with 6 weeks of intravenous antibiotics (4 weeks for highly penicillin sensitive streptococci).

Often we wait until they are stable if they are unstable we use empirical regimens are used unless pathogen specific treatment is available.

For streptococci and enterococci they don’t just look at antibiotic sensitive or resistant they also look at Mean Inhibition Concentration to know whether to use penicillin alone or penicillin and gentamicin. [must remember for exam!]

Valve surgery if necessary (vegetectomy/repair)

Question 25

How effective are antibiotics for treatment of IE?

Answer 25

95% of cases there’s a 4% relapse or reinfection of the same bug

Question 26

How is prosthetic valve IE treated if it’s caused by Staph?

Answer 26

Rifampicin (Biofilm effect) + Gentamicin in Staph (in addition to flucloxacillin (MSAA) or vancomycin (MRSA)

Question 27

How is prosethetic valve IE treated if its strep?

Answer 27

Rifampicin + Gentamicin

Question 28

When must valve surgery be done?

Answer 28

Indications are:
Heart Failure

Cardiac abscess +/- heart block

Large vegetation for left sided IE >1cm

Ongoing embolisation despite antibiotic therapy

Persistent bacteraemiaa despite 7 days antibiotic therapy

Fungal IE (particularly fungal Prosthetic Valve Endocarditis)

IE recurrence rate with modern therapy is low

Question 29

Is giving prophylactic antibiotics prior to dental procedures shown to be a good idea?

Answer 29

There’s no good clinical evidence that prophylactic antibiotics in dental procedures should be given

Question 30

Who should be given prophylactic antibiotics?

Answer 30

Dental procedures in people with:

People with prosthetic cardiac valve/cardiac repair

Previous IE

Congenital heart disease (uncorrected cyanotic defect or corrected with prosthetic material)

Rheumatic heart disease in high risk patients

Cardiac transplants with valvulopathy

Question 31

What should people that are given prophylactic antibiotics be given?

Answer 31

Amoxicillin 2g OD or cephalexin PO or clindamycin 600mg PO in the penicillin allergic