Infective Endocarditis

Question 1

What is infective endocarditis

Answer 1

Infection or inflammation of the endocardium

Question 2

What is the endocardium

Answer 2

Inside surface of the heart and heart valves

Question 3

What is the outcome of infective endocarditis

Answer 3

Leads to significant damage to the valves, requiring them to be replaced

Question 4

What causes infective endocarditis

Answer 4

Microbial colonisation of thrombi on the endocardial surface abnormalities or thrombi on the valve leaflets

Question 5

What are the organisms implicated in infective endocarditis

Answer 5

Mainly oral streptococci

Can be gut strep and staphylococci from the skin

Question 6

What causes infective endocarditis

Answer 6

Bacteria entering usually the mouth, passing into circulation and then settling onto previously damaged areas of heart tissue
These bacteria will cause colonisation within a thrombus and multiply to cause damage and also spread of the infection
This leads to vegetation’s forming

Question 7

What is a vegetation

Answer 7

A mass of platelets, fibrin, microcolonies of microorganisms, and scant inflammatory cells

Question 8

Summarise the changes seen in infective endocarditis

Answer 8

Surface abnormalities cause haemodynamic changes which causes turbulent blood flow in that area leading to platelets and fibrin being deposited on the abnormalities
These thrombi form vegetations on the surface of the valves into which bacteria can spread from the circulation leading to enlargement of the vegetation
The enlargement of the vegetations then cause more surface abnormalities

Question 9

Which group of patients are at the highest risk of infective endocarditis

Answer 9

Older age group

Question 10

What is the most common disease to have at the time of diagnosis of infective endocarditis

Answer 10

No previously known cardiac problem

Question 11

What are common diseases to have when being diagnosed with infective endocarditis

Answer 11

Prosthetic valve

Intracardiac device

Question 12

What are the symptoms of infective endocarditis

Answer 12

Chronic fever
Small haemorrhages beneath the surface of the nails
Changes on the skin
Changing heart murmur

Question 13

How can a diagnosis of infective endocarditis be reached

Answer 13

By taking blood cultures over several days and seeing if bacteria are present in the bloodstream coming form the infection

Question 14

What damage can infective endocarditis cause to valves

Answer 14

Valve dysfunction

Urgent valve replacement needed

Question 15

How is infective endocarditis treated

Answer 15

Prolonged antibiotic treatment
4+ weeks of bacteriocidal treatment
Combination of drugs given venously to ensure it gets to the tissues

Question 16

Which cardiac patients are not a risk of infective endocarditis

Answer 16

Coronary Artery Bypass Grafting
Angioplasty and Stent
Hypokinetic cardiac muscle following an MI
Implanted pacemaker
Implanted defibrillator

Question 17

What type of dental procedures are a risk for infective endocarditis

Answer 17

Procedures involving manipulation of the dento-gingival junction and causing a bacteraemia

Question 18

Give examples of procedures which are a risk of infective endocarditis

Answer 18

Extractions
Periodontal therapy
Gingival surgery
Implants
Restorations - only if the gingival margin is involved or a matrix is used

Question 19

Which dental procedures are questionable when thinking about infective endocarditis risk

Answer 19

Endodontics
Impressions
Orthodontics

Question 20

What can a dentist do for patients at risk of infective endocarditis

Answer 20

Identify them - medical history must cover the risk conditions
Prevent oral disease and keep excellent oral hygiene

Question 21

What is antibiotic prophylaxis

Answer 21

When antibiotics are given as a precaution to prevent rather than to treat

Question 22

How should the decision on using antibiotic prophylaxis be made

Answer 22

Made by the patient and their physician

Communicated to the dentist in writing

Question 23

When should antibiotic prophylaxis be used

Answer 23

Only for procedures likely to produce a significant bacteraemia through manipulation of the dental-gingival junction