Endocarditis

Question 1

How is endocarditis related to Dental Proceedures and poor dentition?

Answer 1

In very rare cases, bacteria in the mouth may trigger endocarditis in people at higher risk.
Here’s what happens: Bacteria found in tooth plaque may multiply and cause gingivitis (gum disease). If not treated, this may become advanced. The gums become inflamed (red and swollen) and often bleed during tooth brushing, flossing, or certain dental procedures involving manipulation of the gums.

When gums bleed, the bacteria can enter the bloodstream and can infect other parts of the body. In the case of endocarditis, this affects the inner lining of the heart and the surfaces of its valves. The bacteria stick to these surfaces and create growths or pockets of bacteria.

Question 2

What precaution should heart disease patients take before dental proceedures?

Answer 2

To prevent endocarditis, patients with certain heart conditions receive a single dose of an antibiotic. You receive it about one hour prior to certain dental treatments.

So not every patient undergoing dental work needs abx

Question 3

Define infective endocarditis

Answer 3

infection of intracardiac endocardial structures (mainly heart valves)

Question 4

Explain the aetiology of infective endocarditis

Answer 4

Most common organisms causing infective endocarditis:

Streptococci (40%) - mainly a-haemolytic S. viridans and S. bovis

Staphylococci (35%) - S. aureus and S. epidermidis

Enterococci (20%) - usually E. faecalis

Other organisms: 
Cardiobacterium 
Coxiella burnetii 
Histoplasma (fungal) 
Haemophilus 
Actinobacillus

Question 5

What is the Pathophysiology of infective endocarditis?

Answer 5

Vegetations form when organisms deposit on the heart valves during a period of bacteraemia

The vegetations are made up of platelets, fibrin and infective organisms

They destroy valve leaflets, invade the myocardium or aortic wall leading to abscess cavities

Activation of the immune system can lead to the formation of immune complexes –> vasculitis, glomerulonephritis, arthritis

Question 6

What are the Risk Factors for infective endocarditis?

Answer 6

Abnormal valves (e.g. congenital, calcification, rheumatic heart disease, trauma)

Recent dental work/poor dental hygiene (source of S. viridans)

Some congenital heart diseases

Prior hx of infective endocarditis

Post heart transplant - cardiac valvulopathy

Weaker;
Intravascular catheter - haemodialysis
Prosthetic heart valves
Iv drug use

Question 7

Recognise the presenting symptoms of infective endocarditis

Answer 7

Arthralgia  
Myalgia  
Headache
SOB
Fever with sweats/chills/rigors  
   -note: this might be relapsing and remitting  
Malaise  
  - Night sweats, Anorexia, , Weight Loss, Fatigue

Others;
Signs of meningism; Confusion etc
Janeway lesions
Oslers nodes

Question 8

Recognise the signs of infective endocarditis on physical examination

Answer 8

Fever !! 90%
Tachycardia
Signs of anaemia - low rbc and tiredness
Clubbing

New regurgitant murmur or muffled heart sounds
Frequency of heart murmurs:
Mitral > Aortic > Tricuspid > Pulmonary

Splenomegaly
Vasculitic Lesions ; Roth spots on retina

Question 9

Identify appropriate investigations for infective endocarditis

Answer 9

Bloods

FBC - high neutrophils, normocytic anaemia

High ESR/CRP

U&Es

NOTE: a lot of patients with infective endocarditis tend to be rheumatoid factor positive

Urinalysis

Microscopic haematuria

Proteinuria

Blood Culture

Do microscopy and sensitivities as well

Echocardiography

Transthoracic or transoesophageal (produces better image)

Duke’s Classification - a method of diagnosing infective endocarditis based on the findings of the investigations and the symptoms/signs

Question 10

which valves most likely to be affected in endocarditis?

Answer 10

Mitral

and Aortic

due to higher left heart pressures more likely to be damaged, bacteria go to damaged valves. hence why rheumatic fever as kid is a risk factor.

Question 11

what are the features of acute rheumativ fever ?

Answer 11

need to know some for paces viva for endocarditis station

Major criteria are as follows:
Carditis (clinical or echocardiographic diagnosis) 50%
Polyarthritis (not monoarthritis) 80%*
Chorea (rare in adults)
Erythema marginatum (uncommon; rare in adults)
Subcutaneous nodules (uncommon; rare in adults)

Minor criteria are as follows:
Polyarthralgia (cannot count arthritis as a major criterion and arthralgia as a minor criterion)
Fever exceeding 38.5°C
Elevated ESR (>60 mm/hr) or CRP level (>3 mg/L)
Prolonged PR interval aka 1st degree heart block
Fever, multiple painful joints,
polyarthritis