25. Valvular heart disease Flashcards Preview

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Flashcards in 25. Valvular heart disease Deck (24):

What is meant by valvular heart disease?

Any disease involving one of the four valves of the heart - these conditions occur largely due to ageing

Going to talk about the left sided valve lesions


What are the different types of left sided valve lesions?

Mitral valve prolapse (most common and least important)
Aortic stenosis/regurgitation
Mitral regurgitation
Mitral stenosis


What is the normal functioning of the mitral valve?

Opens during diastole to allow the filling of the left ventricle from the left atrium
Closes in systole to allow left ventricle generates pressure and forces blood from the aorta


What is meant by mitral valve prolapse?

When the mitral valve leaflets have a level of redundancy in them - they are floppy
As the ventricle contracts, the valve gets pushed up into the left atrium and there is a prolapse

(There may be a degree of blood leaking back into the left atrium i.e. mitral regurgitation)


What are the signs and symptoms of mitral valve prolapse?

Generally asymptomatic

Ejection click and late systolic murmur


What is meant by aortic stenosis?

This is a narrowing of the aortic valve, restricting blood flow through the aorta

The heart must contract to a greater degree to pump the blood into the aorta


What are the causes of aortic stenosis

Natural calcification and degeneration of the three valve leaflets with age - generally presents in 70s and 80s

Congenital bicuspid valve i.e. born with just two leaflets rather than three - the valve works fine but wears out a bit earlier - generally presents in 50s and 60s

Can be due to rheumatic heart disease


What is rheumatic heart disease?

Group A strep infections can cause the development of rheumatic fever - an autoimmune reaction to the infection
This is an inflammatory disease - the mitral and the aortic valve can become inflamed
The inflamed valves scar and become thickened - they leak and become narrowed and do not move properly - stenosis has occurred


What is the impact of aortic stenosis on the left ventricle?

As the left ventricles needs to generate more pressure to eject the blood through the aortic valve, the ventricle wall thickens and left ventricular hypertrophy occurs

Results in angina and left ventricular failure


What is the effect of aortic stenosis on the lungs?

Increased stiffness of the lungs occurs - in order to generate the increased pressure in the left ventricle, there is an increased pulmonary pressure from the lungs
A significantly increased pulmonary pressure can cause a fluid leakage into the lungs causing stiff lungs

Results in dyspnoea


What are the signs of aortic stenosis and explain these

Slow rising carotid pulse - the ventricle is pushing blood against the valve and against an increased pressure so the pulsation is SLOW
Ejection murmur heart during systole
Fourth heart sound


What is the key investigation for an aortic stenosis and why?


ECG (electrocardiogram) is useful but doesn't say why there is hypertrophy i.e. may just be due to hypertension


What are the indications for surgery in aortic stenosis?

If there are any symptoms - surgery
If there is left ventricular dilation - surgery

The prognosis following surgery is outstanding


What is aortic regurgitation?

This is a leakage of the aortic valve every time the left ventricle relaxes (into the left atrium)


What are the causes of aortic regurgitation?

Caused by anything that would cause damage to the valve leaflets:
Congenital bicuspid valve
Rheumatic disease
Infective endocarditis

OR caused by factors which can cause dilation of the leaflet roots and so the edges of the leaflets do not all meet together as they should e.g. marfan syndrome


What are the symptoms of aortic regurgitation?

Often asymptomatic and as time goes on, symptoms start to appear:


What are the signs of aortic regurgitation?

Rapidly rising carotid pulse
Early diastolic murmur
Ejection murmur


What is the treatment for aortic regurgitation?

Once the patient has symptoms - surgical replacement of the valve


What is mitral stenosis and what is it caused by?

Narrowing of the mitral valve - the left ventricle will not fill properly

Due to rheumatic fever - only one cause


What is the impact of mitral stenosis on the heart and why?

Narrowing of mitral valve so the left ventricle does not fill up properly - SO the left atrial pressure increases - leads to huge left atrial dilatation


What is the consequence of mitral stenosis?

Left atrial dilatation destroys the conduction system - all the conduction fibres in the atria are damaged and the patient goes into atrial fibrillation

MUST coagulate the patient


What is mitral regurgitation?

Leakage back through the mitral valve every time the left ventricle contracts


What is the cause of mitral regurgitation?

Occurs due to any problem of the valve leaflets e.g. mitral valve prolapse, rheumatic disease


What is the general treatment for valvular heart disease?

Fluid retention - diuretics
Beta blockers
Anticoagulants to protect against systemic embolisation