Endocarditis
- Inflammation of the inner lining of the heart, the endocardium
- Infective endocarditis is caused by pathogens such as bacteria
- Common in elderly patients and those with pre-existing heart conditions such as congenital
heart failure, atherosclerotic aortic valve disease and rheumatic heart disease
- Also, individuals who have had prosthetic valve heart surgery and those with drug
addictions are thought to be more at risk
Pathophysiology
- Infection occurs when there is a high pressure gradient and turbulence around a valve/
septal defect
- This causes the roughening of the endothelium, leading to the deposition of fibrins and
platelets. Organisms which may enter the blood reach the fibrin-platelet layer, leading to
microbial vegetations
- Common symptoms of endocarditis include tiredness, anaemia, heart murmurs, fever,
muscle/joint pain, nausea and a cough/ shortness of breath
- Causative agents are usually bacterial, however some cases can be caused by fungal and
chlamydia infections
- Bacterial:
‘Streptococcus viridans’ group – although cases caused by this bacterium
are decreasing, it is still the leading agent of late onset endocarditis. The
viridans streptococci enter the blood via the gums, usually following a dental
procedure
Streptococcus faecalis – more common in older male patients with
genitourinary disease. The bacterium enters the blood following GU tract
manipulation. S. faecalis is noted for its reduced sensitivity to penicillin
Staphylococcus aureus – clinical features often include staphylococcal
septicaemia. S. aureus usually attacks previously healthy valves, particularly
the aorta. This bacterium may enter the blood stream from a septic skin
focus or from infected lungs. Drug addicts are particularly at risk of
developing S. aureus septicaemia
Staphylococcus epidermidis – an important cause of endocarditis following
cardiac surgery. This species may enter the blood stream from the patient’s
skin or the skin of the surgeon
Haemophilus sp. – H. para-influenzae, H. influenzae and H. aphrophilus are
uncommon causes of endocarditis, mainly affecting younger patients than
Streptococci, entering the bloodstream via the respiratory tract
Gram negative bacilli – Escherichia coli, Klebsiella aerogenes,
Pseudomonas sp., Bacteroides fragilis and others may enter the
- Inflammation of the inner lining of the heart, the endocardium
- Infective endocarditis is caused by pathogens such as bacteria
- Common in elderly patients and those with pre-existing heart conditions such as congenital
heart failure, atherosclerotic aortic valve disease and rheumatic heart disease
- Also, individuals who have had prosthetic valve heart surgery and those with drug
addictions are thought to be more at risk
Pathophysiology
- Infection occurs when there is a high pressure gradient and turbulence around a valve/
septal defect
- This causes the roughening of the endothelium, leading to the deposition of fibrins and
platelets. Organisms which may enter the blood reach the fibrin-platelet layer, leading to
microbial vegetations
- Common symptoms of endocarditis include tiredness, anaemia, heart murmurs, fever,
muscle/joint pain, nausea and a cough/ shortness of breath
- Causative agents are usually bacterial, however some cases can be caused by fungal and
chlamydia infections
- Bacterial:
‘Streptococcus viridans’ group – although cases caused by this bacterium
are decreasing, it is still the leading agent of late onset endocarditis. The
viridans streptococci enter the blood via the gums, usually following a dental
procedure
Streptococcus faecalis – more common in older male patients with
genitourinary disease. The bacterium enters the blood following GU tract
manipulation. S. faecalis is noted for its reduced sensitivity to penicillin
Staphylococcus aureus – clinical features often include staphylococcal
septicaemia. S. aureus usually attacks previously healthy valves, particularly
the aorta. This bacterium may enter the blood stream from a septic skin
focus or from infected lungs. Drug addicts are particularly at risk of
developing S. aureus septicaemia
Staphylococcus epidermidis – an important cause of endocarditis following
cardiac surgery. This species may enter the blood stream from the patient’s
skin or the skin of the surgeon
Haemophilus sp. – H. para-influenzae, H. influenzae and H. aphrophilus are
uncommon causes of endocarditis, mainly affecting younger patients than
Streptococci, entering the bloodstream via the respiratory tract
Gram negative bacilli – Escherichia coli, Klebsiella aerogenes,
Pseudomonas sp., Bacteroides fragilis and others may enter the
