Valvular Disease Flashcards
Stenosis definition
narrowing of valve outlet caused by thickening of valve cusps/increased rigidity or scarring
Incompetence definition
(insufficency/regurgitation)
incomplete seal when valves close allowing blood to flow backwards
What valves are making the first heart sound?
- mitral
- tricuspid
- systole
What valves are making the second heart sound?
- aorta
- pulmonary
- diastole
What are the common causes of valve stenosis and incompetence?
- congenital heart disease:
- bicuspid valve
- atresia
- cardiomyopathy:
- hypertrophic
- dilated
- acquired:
- rheumatic fever
- MI
- age-related: idiopathic calcific stenosis
- endocarditis
What are the risks of aortic stenosis?
- LVH
- syncope
- sudden cardiac death
What causes aortic stenosis?
- calcification of congenital bicuspid valve
- senile calcific degeneration (calcification of leaflets, diallowing normal opening of cusps)
- rheumatic fever
What are the clinical symptoms of aortic stenosis?
- dyspnoea
- angina
- syncope
What are the causes of aortic incompetence?
- infective endocarditis
- rheumatic fever
- Marfan’s Syndrome
What are the consequences of aortic regurgitation?
- increases volume of blood to be pumped
- increases work of heart
- hypertrophy and failure
- can occur with aortic stenosis
What are the causes of mitral incompetence?
- cusp/chordae damage:
- rheumatic heart disease: scarring/contraction
- floppy valve and Marfan syndrome: stretch
- infective endocarditis: perforation
- papillary muscle/valve ring damage:
- post MI
What are the risks of mitral valve incompetence?
- pulmonary hypertension
- RVH
Describe the progression of mitral stenosis
- restricted blood flow to left ventricle
- AF
- back pressure results in pulmonary hypertension
- right heart failure
What is the definition of infective endocarditis?
- infection of valve with formation of thrombotic vegetations (aggregations of fibrin and platelets)
- virulence of organisms which caused the infection depends on the damage and severity of the clinical illness
- classified as acute/sub-acute
- bacteraemia common
What are the risk factors for infective endocarditis?
- valve damage (post rheumatic fever)
- bacteraemia (dental/catheterisation/IV drug abuse)
- immunosuppression
Describe rheumatic fever
- acute multisystem disease
- affects heart (myocarditis/valvulitis/pericarditis), joints, connective tissue
- 3 weeks post streptococcal infection
- immune mediated infection
- affects children
- can be recurrent
- chronic valve disease decades later
Describe the local and systemic complications of infective endocarditis
- splinter haemorrhages/clubbing in nails
- anaemia
- bronchopneumonia
- myocarditis
Acute native valve endocarditis
- valves can be normal
- aggressive
- virulent organisms including S.aureus and group B streptococci
Sub-acute native valve endocarditis
- abnormal valves
- can be painless but can deteriorate
- virulent organisms include a-haemolytic streptococci, enterococci
Prosthetic valve endocarditis
- mitral more susceptible than aortic
- early onset: S.aureus, gram negative bacilli, candida
- late onset: staphylococci, a-haemolytic streptococci, enterococci
Valve disease in IV drug users
- majority have no underlying valvular abnormalities
- half of cases is tricuspid vlave
- S.aureus most common
Treatment of infective endocarditis
- treat strep infection with antibiotics
- prophylactic cover for invasive procedures
- replace damaged valves
- if suspicion clinically:
- imaging: echocardiography
- blood culture
- IV antibiotics
