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Flashcards in Valvular Heart Disease Deck (31)

What is valvular heart disease?

Functional deficiency of the heart valves


How many cardiac valves and describe them?

4 valves:
2 atrioventricular valves allow blood flow from atrium to ventricle (Tricuspid on the right and mitral on the left)
2 outlet valves allow blood from ventricles to arteries (Pulmonary allows blood from the right ventricle into the pulmonay artery, Aortic allows blood from the left ventricle into the aorta)


What type of valve are all the heart valves?

Non return valves


What are the two types of valvular heart disease?

Valvular stenosis
Valvular incompetance (regurgitation)


What is valvular stenosis?

Narrowing of the valve, limiting the quantity of blood passing through


What is valvular incompetance?

Failure of the non return function of the valve leads to valvular regurgitation


What are the consequences of valvular heart disease?

Decrease in cardiac output - poor function, exercise intolerance, left ventircular hypertrophy, left ventricular failure, sudden death
Infection - damaged vessels susceptible, infective endocarditis


What are the 4 causes of left heart valvular disease?

Mitral Stenosis
Mitral Regurgitation
Aortic Stenosis
Aortic Regurgitation


What is mitral stenosis?

Left heart valvular disease.
Narrowing of the mitral valve, thickening of the valve leaflets with calcification and closure of the commisures.
Complications: heart failure, atrial fibrillation, Infective endocarditis


What causes mitral stenosis

Degenerative mitral stenosis associated with age related calcification
Rheumatic heart disease


What is mitral regurgitation?

Left heart valvular disease.
A diseased valve fails to close properly and leaks.
Complications: heart failure, atrial fibrillation, endocarditis risk.


What causes mitral regurgitation?

Rheumatic heart disease, bacterial endocariditis, mitral valve prolapse, ischaemic heart disease resulting in rupture of papillary muscle/chordae tendonae, cardiomyopathy,


What is aortic stenosis?

Left heart valvular disease. Narrowing of the aortic valve.
Results in obstruction to the left ventricular flow.


What causes aortic stenosis?

Congential bicuspid valve, degenerative calcification, rheumatic heart disease


What is aortic regurgitation?

Left heart valvular disease.
Arises from valve dysfunction or incompetace or dilation of the aortic root.


What causes aortic regurgitation?

rheumatic heart disease, hypertension, syphilis, marfans syndrome, ehlers - danlos syndrome, osteogenesis imperfecta, idiopathic aortic root dilation, endocarditis


What are the 2 causes of right heart valvular disease?

Tricuspid stenosis - most commonly caused by rheumatic fever
Triscupid regurgitation - due to right ventricular enlargement which has been caused by rheumatic heart disease, congenital heart disease or endocarditis secondary to IV drug use/abuse.


What is rheumatic heart disease?

Consequence of acute rheumatic fever which occurs 2 -3 weeks after group A streptococcal infection in the throat


Complication of rheumatic heart disease?

Antibody cross reactivity which causes:
Heart - pericarditis, myocarditis, endocarditis
Joints - polyarthritis
Skin - nodules, skin rashes
Arteries - arteritis


What % of children with acute rheumatic fever never fully recover?



What % of those who have suffered an episode of rheumatic fever will develop chronic scarring of mitral valve cusps?

10 - 15%


What is the consequence of scarring on mitral valve cusps?

Scarring thickens the valve cusps and fuses the commissures of the cusps leading to valve stenosis


What is infective endocarditis?

An acute or chronic disease from infection of a focal area of the endocardium. A heart valve is usually involved but the process may affect the mural endocardium of the atrium or ventricle, or a congenital defect such as a patent ductus arteriosus.


Describe acute infective endocarditis?

Destructive infection of a previously normal heart valve with a highly virulent organism (e.g. S. aureus)


Describe Subacute infective endocarditis?

Insidious disease, infection of a previously abnormal valve with organisms of low virulence (e.g. S. viridans)


Where is the source of organisms for infective endocarditis?

Oropharynx - strep
Resp Tract
Skin - strep and candida
GI and urinary tract - strep faecalis


What is the main organism for infective endocarditis?

Strep Viridans - 60%


What are vegetations?

Lesions of infective endocarditis, composed of bacterial colonies and thrombotic debris.
They stick to the cusps of the valve


Where does most infective endocarcitis occur?

95% occurs in left sided valves (mitral and aortic) and most cases occur in previously damaged valves.


Describe vegetation formation?

1) Endocardial injury followed by a focal adherence of platelets and fibrin
2)Initially sterile platelet - fibrin area become secondarily infected by microorganisms circulating in the blood, either from a distant source or as a result of transient bacteraemia from mucosal / skin source.


Consequences of medications linked to infective endocarditis?

Anticoagulants - bleeding risk
Calcium channel blockers - gingival hyperplasia
Beta blockers, ACE inhibitors, diuretics - oral drug reactions