Valvular Heart Disease Flashcards
what is stenosis?
narrowing of outlet so blood can’t get through
the valve isn’t opening properly
what is the effect of stenosis on heart?
heart therefore has to pump harder
can’t push the blood out, the pressure of the blood behind the stenotic valve is going to decrease ventricle therefore has to work harder
what happens to the flow of blood as a result of stenosis? what effect does this have?
the flow of blood following stenosis is reduced
if flow in coronary arteries is reduced then blood supply to the hypertrophic muscle may be compromised
what leads to stenosis?
thickening of valve cusps as a result of atherosclerosis
increased rigidity due to scarring
what is valve incompetence?
valves allow the blood to go forward but are loose and therefore don’t close resulting in back flow of blood
what is the effect of valve incompetence?
pump has to be pumped harder to get blood through valve because some of the blood will flow back
except a higher systolic pressure but lower diastolic
describe the composition of vegetation and how it forms
damage on a valve cusp that is a modified bit of intravascular material
platelets stick and thrombin can then accumulate
the valve may become damaged by infection, vasculitis then platelets and thrombin are deposited on top of that
what is the effect of vegetation?
valvs dont close properly
organisation of vegetation and fibrosis and calcification you can get distortion of valve = incompetence or it can be less mobile leading to it becoming stenosed
how does congenital heart disease cause valve stenosis and incompetence?
bicuspid aortic valve more likely to have problems with corners which in time could lead to stenosis
how do cardiomyopathies lead to valve problems?
hypertrophic heart, heart gets to big because you have a primary problem with myocardium causing the ring to become dilated causing the valves to open and cusps don’t close properly
extra workload on the heart increases O2 demand
what acquired conditions can lead to valve issues?
rheumatic fever, MI (valves don’t work because of damaged papillary muscles), age related, endocarditis
how does aortic stenosis form?
heavy calcification because of damage to cusps therefore you have platelets and fibrin deposited
organisation and calcification of fibrous tissue
what is aortic stenosis?
cusps of aortic valve can be fixed and blood struggles to get through because of stenosis but valve can leak blood back through because it is incompetent
what are the risks of aortic stenosis ?
incompetence- left heart working to push blood through, but blood flows back, harder to get blood to flow from R side to L because blood flowing back in left
L and R ventricular hypertrophy
O2 demand of coronary arteries increases, problems such as atherosclerosis O2 demand is high affects both sides
sudden death- if don’t get enough blood and if for a moment you don’t get enough blood to the brain you can drop= syncope or death
what are the main causes of aortic stenosis?
calcification of congenital bicuspid valve
rheumatic fever= damage and abnormal structure to the valve
senile calcification degradation- accumulation of damage
