Valvular Heart Disease

Question 1

What is valvular heart disease?

Answer 1

Functional deficiency of the heart valves

Question 2

How many cardiac valves and describe them?

Answer 2

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)

Question 3

What type of valve are all the heart valves?

Answer 3

Non return valves

Question 4

What are the two types of valvular heart disease?

Answer 4

Valvular stenosis
Valvular incompetance (regurgitation)

Question 5

What is valvular stenosis?

Answer 5

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

Question 6

What is valvular incompetance?

Answer 6

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

Question 7

What are the consequences of valvular heart disease?

Answer 7

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

Question 8

What are the 4 causes of left heart valvular disease?

Answer 8

Mitral Stenosis
Mitral Regurgitation
Aortic Stenosis
Aortic Regurgitation

Question 9

What is mitral stenosis?

Answer 9

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

Question 10

What causes mitral stenosis

Answer 10

Degenerative mitral stenosis associated with age related calcification
Rheumatic heart disease

Question 11

What is mitral regurgitation?

Answer 11

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

Question 12

What causes mitral regurgitation?

Answer 12

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

Question 13

What is aortic stenosis?

Answer 13

Left heart valvular disease. Narrowing of the aortic valve.

Results in obstruction to the left ventricular flow.

Question 14

What causes aortic stenosis?

Answer 14

Congential bicuspid valve, degenerative calcification, rheumatic heart disease

Question 15

What is aortic regurgitation?

Answer 15

Left heart valvular disease.

Arises from valve dysfunction or incompetace or dilation of the aortic root.

Question 16

What causes aortic regurgitation?

Answer 16

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

Question 17

What are the 2 causes of right heart valvular disease?

Answer 17

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.

Question 18

What is rheumatic heart disease?

Answer 18

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

Question 19

Complication of rheumatic heart disease?

Answer 19

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

Question 20

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

Answer 20

95%

Question 21

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

Answer 21

10 - 15%

Question 22

What is the consequence of scarring on mitral valve cusps?

Answer 22

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

Question 23

What is infective endocarditis?

Answer 23

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.

Question 24

Describe acute infective endocarditis?

Answer 24

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

Question 25

Describe Subacute infective endocarditis?

Answer 25

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

Question 26

Where is the source of organisms for infective endocarditis?

Answer 26

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

Question 27

What is the main organism for infective endocarditis?

Answer 27

Strep Viridans - 60%

Question 28

What are vegetations?

Answer 28

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

Question 29

Where does most infective endocarcitis occur?

Answer 29

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

Question 30

Describe vegetation formation?

Answer 30

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.

Question 31

Consequences of medications linked to infective endocarditis?

Answer 31

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