Infective Endocarditis

Question 1

Definition of infective endocarditis

Answer 1

• Infection of endcardial surface of heart by bacteria and settle in the heart lining, heart valve, blood vessel, mural endocardium, septal defect
• predominantly affects natural heart valve
• can also affect prosthetic heart valve
• congenital heart defect : coarctation of aorta, ductus arteriosus

Question 2

Predisposing factors Infective Endocarditis

Answer 2

• Dental / Surgical procedures
• Contaminated IV drug use (right sided valve involvement)
• Obvious skin infections
• Occult source from gut, oral cavity (enterococcus faecalis, s. bovis)
• Intravascular catheter infection
• Nosocomial wounds
• Chronic invasive procedures
• Trivial injury

Question 3

Classification of infective endocarditis

Answer 3

• Native valve endocarditis (NVE) : acute / subacute
• Prosthetic valve endocarditis (PVE) : early / late
• Intravenous drug abuse endocarditis (IVDA)

Question 4

Acute bacterial endocarditis
vs
Subacute bacterial endocarditis
vs
Prosthetic valve endocarditis
vs
IV drug abuse endocarditis

Answer 4

Acute bacterial endocarditis
- Staphylococcus aureus
- NO clubbing, splenomegaly, petechial haemorrhage
- Normal valves affected
- Metastatic common
- Rapid, aggresive course
- Fatal if not treated promptly

Subacute bacterial endocarditis
- Streptococcus viridans (brushing, chewing, dental procedures)
- HACEK (Haemophilus, Actinobacillus, Kingella)
- Clubbing, Splenomegaly, Petechial haemorrhage found
- Metastatic spread less common
- Only abnormal valves affected (abnormal turbulence of blood flow caused by damage/defect)
- Indolent course

Prosthetic valve endocarditis
- Staphylococcus epidermidis
- Cardiac prosthetic valve, cardiac venous catheters affected
- Due to coagulase negativity

IV drug abuse endocarditis
- Staphylococcus aureus
- Candida albicans
- venepuncture without aseptic measure (right sided valve affected) : tricuspid / pulmonary valve infection

Question 5

Clinical manifestation of Infective endocarditis

Answer 5

cardiac disease with persistent fever

Question 6

Symptoms of infective endocarditis

Answer 6

Onset of symptoms : in 2 weeks or less

Acute :
- high grade fever and chills
- shortness of breath
- arthralgia
- myalgia
- abdominal pain
- pleuritic chest pain
- back pain

Subacute :
- low grade fever
- anorexia (loss of appetite)
- weight loss
- fatigue
- nausea
- vomiting
- arthralgia
- myalgia
- abdominal pain