Valvular Disease; infective endocarditis Flashcards
What is the function of a valve?
To allow forward flow of blood but prevent back-flow
What are the 4 components of valves?
- Valve ring
- Cusp
- Chordae tendinea
- Papillary muscle (mitral and tricuspid only)
What is vegetation?
Damage to the covering of valves forming thrombi; this results in the valve becoming calcified and not closing properly
What does valvular heart disease describe?
Any part of the valve is dysfunctional
Give 4 examples of functional failure in valves
- Mitral stenosis
- Mitral incompetence
- Aortic stenosis
- Aortic incompetence
What is stenosis?
Narrowing of the valve outlet caused by thickening of valve cusps, or increased rigidity or scarring
What is incompetence or insufficiency
Regurgitation is caused by an incompetent seal when valves close allowing blood to floe backwards
What is backflow of blood?
output is going in the wrong direction
The closing of what valves cause the first heart sound?
Mitral and tricuspid
The closing of what valves cause the second heart sound?
aortic and pulmonary valves
What are the common causes of valve stenosis and incompetence?
- Congenital heart disease
- Cardiomyopathy (hypertrophy)
- Acquired:
- Rheumatic fever
- Myocardial infarction
- age related - calcification
- endocarditis
What is atresia?
absense or abnormal narrowing of an opening or passage in the body
Risks of aortic stenosis
- Left ventricular hypertrophy
- Syncope
- Sudden cardiac death
Causes of aortic stenosis
- Calcification of congenital bicuspid valve
- Senile calcification degeneration
- Rheumatic fever
Consequences of aortic stenosis
- Increases the work of the heart
- Ventricular hypertrophy (LHS)
- Causes cardiac failure late in clinical course
Clinical symptoms of aortic stenosis
- Dyspnoea
- Angina
- Syncioe
- Orthopnea
Causes of aortic incompetence
- Infective endocarditis
- Rheumatic fever
- Marfan’s syndrome
What is Marfan’s Syndrome?
CT disorder; results in collagen deficiency and non-elastic skin
What occurs in aortic regurgitation?
- Increases the volume of blood to be pumped signficantly
- Increases the work of the heart (CO)
- Cardiac hypertrophy
- Cardiac failure
**Can occur in the presence of aortic stenosis
Causes of mitral incompetence
- Cusp damage
- Rheumatic heart disease
- Floppy vakve and Marfan syndrome
- Infective endocarditis
- Chordaw tendinae
- Papillary muscle
- Valve ring
Risks of mitral incompetence
- Pulmonary hypertension
- RV hypertrophy
**Almost always post-rheumatic fever
When and where does mitral stenosis occur?
- Congenital (rare)
- Post rheumatic fever
- Developing countries
What does mitral stenosis restrict?
blood flow to LV
What can mitral stenosis cause?
- Atrial fibrillation
- Back pressure results in pulmonary hypertension
- Right heart failure
What is infective endocarditis?
Infection of valve with formation of thrombotic vegetations (abnormal growth)
What determines the damage and severity of endocarditis?
Virulence
What is the most common type of endocarditis?
Bacteraemia
What are the risk factors for infective endocarditis?
- Valve damage
- Bacteraemia
- Dental
- Catherisation
- 10% unknown
- IV drug abuse
- Immunosuppression
What is rheumatic fever?
Acute multisystem diseas affecting the heart, joints and CT
When does rheumatic fever occur?
3 weeks post streoptococcal infection
Is rheumatic fever immune mediated rather than direct infection
immune mediated
Who does rheumatic fever occur in?
Children aged 4-16
What is the long term effect of rheumatic fever?
Chronic valve disease
What are the local and systemic complications of infective endocarditis?
- Cerebral and retinal emboli
- Myocarditis
- Splenomegaly
- Anaemia
- Bronchopneumonia, pulmonary infarct (tricuspid endocarditis)
- Renal infarcts, glomerulonephritis
- Haematuria
- Splinter haemorrahges
- Clubbing
What is acute native valve endocarditis?
- Valves may be normal
- Aggressive disease
- Virulent organusms such as staph aureaus and group B streptococci
What is a native valve?
A valve you are born with
Subacute native valve endocarditis
- Abnormal valves
- Indolent but may deteriorate
- Alpha-haemolytic streptococci, enterococci (urinary catheter)
How to treat infective endocarditis?
- Treat strep with antibiotics
- Prophylatic cover for invasive procedures
- Replace damaged valves
What causes early onset endocarditis?
- staph aureus
- gram negative bacilli
- candida species
What causes late onset endocarditis?
- straphylococci
- alpha-haemolytic
- streptococci
- enterococci
What valve is prosthetic valve endocarditis more likely in?
mitral is more likely than aortic
What method should be used to administer antibiotics in endocarditis?
IV route
