25. Valvular heart disease Flashcards
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?
Echocardiogram
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: Calcification 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
