Valvular Heart Disease

Question 1

What are the components and functions of vales

Answer 1

Function - Allow forward flow but to prevent backflow.

Components - Valve ring, cusp, cordae, and papillary muscles (only for tricuspid and mitral)

Question 2

Name the functional failure in valves

Answer 2

Mitral stenosis or incompetence, aortic stenosis or incompetence. Tricuspid and pulmonary valve stenosis or incompetence but this is less common and less severe.

Question 3

Define stenosis

Answer 3

Narrowing of valve outlet caused by thickening of valve cusps or increased rigidity or scarring

Question 4

Define incompetence

Answer 4

Insufficiency or regurgitation caused by incomplete seal when valves close allowing for blood to flow backwards

Question 5

What are vegitations?

Answer 5

Lesions or growths on your heart valves that occur with endocarditis

Question 6

When do you hear the valve sounds?

Answer 6

Tricuspid and mitral in systole. Aortic and pulmonary in diastole

Question 7

What are some of the common generic causes of cardiac valve stenosis and incompetence?

Answer 7

• Congenital heart disease (Bicuspid valve and atresia)
• Cardiomyopathy (Hypertrophic or dilated)
• Acquired (Rheumatic fever, myocardial infarction, age related (calcification) or endocarditis)

Question 8

What are some risks of aortic stenosis?

Answer 8

Left ventricular hypertrophy, syncope and sudden cardiac death.

Question 9

Name some aortic stenosis causes

Answer 9

• Calcification of a congenital bicuspid valve,
• Senile/idiopathic calcification degeneration,
• Rheumatic fever

Question 10

What are consequences of aortic stenosis?

Answer 10

Increased work of the heart leading to ventricular hypertrophy/ Can lead to cardiac failure. Symptoms include dyspnoea, angina and syncope.

Question 11

What are some causes of aortic incompetence?

Answer 11

• Infective endocarditic,
• Rheumatic fever
• Marfan’s syndrome

Question 12

What are the consequences of aortic regurgitation?

Answer 12

Increases the volume of blood the heart needs to pump as a portion of it will flow back into ventricles. This increases work which can cause cardiac hypertrophy and can lead to cardiac failure.

Question 13

What are some causes of mitral incompetence?

Answer 13

Cusp damage - Rheumatic heart disease (scarring, contraction) Marfan syndrome (stretch), Infective endocarditis (perforation).
Chordae - (same causes as above),
Papillary Muscle - Post MI,
Valve ring - same as above and aging.

Question 14

What are some of the risks of mitral incompetence?

Answer 14

Pulmonary hypertension or right ventricular hypertrophy

Question 15

What are some of the consequences of mitral stenosis?

Answer 15

Restricts blood flow to left ventricles, atrial fibrillation, back pressure resulting in pulmonary hypertension and finally causes right heart failure

Question 16

Define infective endocarditis

Answer 16

Infection of valves or endocardium with formation of thrombotic vegetations.
As blood is constantly moving past valves very quickly then its difficult to get build up of chemotactic factors.

Question 17

Risk factors for infective endocarditis

Answer 17

Valve damage (Especially post rheumatic fever).
Bacteraemia - Presence of bacteria in circulation, can be due to dental work, catheterisation, IV drug abuse.
Immunosuppression

Question 18

What is Rheumatic fever?

Answer 18

Acute multisystem disease - affecting heart, joints and connective tissue. Normally occurs 3 weeks post streptococcal infection and is an immune mediated rather than direct infection. Real issue as it can cause chronic valve disease decades later.

Question 19

Describe the composition of a vegetation

Answer 19

Mass of platelets, fibrin, microcolonies of microorganisms (most commonly group D streptococcus, gut commensals and skin strep), and scant inflammatory cells

Question 20

What are some of the local and systemic complications of infective endocarditis

Answer 20

• Cardiac failure
• Fever
• Splinter Haemorrhages
• Clubbing
• Joint pain
• Haematuria
• Primary kidney
• Lung Disease

Question 21

Describe Acute Native Vale Endocarditis

Answer 21

Valves may be normal but infected by a very virulent organisms (staph. aureus) meaning it is an aggressive disease

Question 22

Describe subacute native valve endocarditis

Answer 22

Occurs with abnormal valves and may be indolent but can deteriorate. Can be caused by alpha-haemolytic streptococci and enterococci

Question 23

Describe features of prosthetic valve endocarditis

Answer 23

• Where mechanical and bio-prosthetic valves become infected (5%).
• Mitral valves more susceptible than aortic.
• Early onset caused by staph.aureus, gram negative bacilli or candida species.
• Late onset caused by alpha-haemolytic streptococci or enterococci

Question 24

What are some ways to prevent infective endocarditis?

Answer 24

Treat strep infections with antibiotics, for patients with history of rheumatic fever then give prophylactic cover for invasive procedures such as dental work and replace damaged valves.

Question 25

What are some of the principles of diagnosis and treatment of infective endocarditis

Answer 25

Clinical suspicion and signs, imaging (ECHO) and take many blood cultures. Then treat with IV antibiotics.