Valvular disease Flashcards
Valvular disease is more common in which valves?
Aortic valve
Mitral valve
What is valve stenosis?
Valve doesn’t open enough
What is valve regurgitation?
Valve doesn’t close fully
What are the causes of aortic valve stenosis?
Degenerative fibrosis
Degenerative calcification
Chronic rheumatic fever
What causes degenerative fibrosis and calcification in aortic valve stenosis?
Valves face stress over time
become damaged
What predisposes to degenerative fibrosis and calcification of the aortic valve? Why?
Congenital bicuspid form of the valve
Because has two cusps instead of three
more stress per cusp
increased damage
How does chronic rheumatic fever cause valve stenosis?
Inflammation of valve,
fibrosis of valve,
cusps fuse together
What are the consequences of aortic valve stenosis?
LV hypertrophy
Left-sided heart failure
Microangiopathic haemolytic anaemia
How does aortic valve stenosis lead to LV hypertrophy?
Stenosed aortic valve increases resistance to blood flow out of LV
LV has to contract harder, generate more pressure to push blood through stenosed aortic valve
How does aortic valve stenosis lead to left-sided heart failure?
Stenosed aortic valve decreases blood flow out of LV
LV hypertrophy not maintained, LV wall thins, LV dilates
What are some of the symptoms of left-sided heart failure?
Angina
Syncope
What causes angina?
Decreased blood flow to myocardium
What causes syncope?
Decreased blood flow to CNS
How does aortic valve stenosis lead to microangiopathic haemolytic anaemia?
Red blood cells broken up as pass through stenosed aortic valve
What is the abnormal heart sound with aortic valve stenosis?
Why?
Crescendo-decrescendo murmur
louder and then quieter
by rapid ejection then reduced ejection giving
turbulent blood flow across stenosed aortic valve
What are the causes of mitral valve stenosis?
Chronic rheumatic fever
How does chronic rheumatic fever cause mitral valve stenosis?
Inflammation of valve,
fibrosis of valve,
cusps fuse together
What are the consequences of mitral valve stenosis?
LA dilation
Pulmonary hypertension
How does mitral valve stenosis lead to LA dilation?
Stenosed mitral valve increases resistance to blood flow out of LA
less blood flow out of LA
increased blood volume and blood pressure in LA
What are the consequences of LA dilation?
Atrial fibrillation
Oesophagus compression
How does LA dilation lead to atrial fibrillation?
LA dilation stretches atrial myocytes
damages them
What is the risk of atrial fibrillation? How?
Thrombus formation
due to stagnant pools of blood forming in the atria
What is the symptom of oesophageal compression?
Dysphagia - difficulty swallowing
How does mitral valve stenosis lead to pulmonary hypertension?
Blood backs up in the LA, pulmonary veins and pulmonary arteries
giving increased blood pressure in them
What are the consequences of pulmonary hypertension?
Pulmonary oedema
RV hypertrophy
What is the symptom of pulmonary oedema?
Dyspnoea - difficulty breathing
How does pulmonary hypertension lead to RV hypertrophy?
RV has to contract harder to generate more pressure to push blood through the pulmonary circulation
What is the abnormal heart sound with mitral valve stenosis? Why?
Snap as valve opens
Diastolic rumble
turbulent blood flow across stenosed mitral valve in diastole
What are the causes of aortic valve regurgitation?
Aortic root dilation
Chronic rheumatic fever
How does aortic root dilation cause aortic valve regurgitation?
Pulls valve cusps apart
How does chronic rheumatic fever cause aortic valve regurgitation?
Inflammation of valve,
fibrosis of valve,
cusps don’t fit together
What are the consequences of aortic valve regurgitation?
Bounding pulse
LV dilation
What are the signs of a bounding pulse?
Head bobbing with each heartbeat
Quince’s sign - flushing of nails with each heartbeat
How does aortic valve regurgitation cause a bounding pulse?
Blood flows back into LV from aorta in diastole
diastolic pressure decreases
Increased EDV leads to increased stroke volume in following systole
systolic pressure increases
How does aortic valve regurgitation lead to LV dilation?
LV has increased EDV and EDP
becomes stretched
What is the abnormal heart sound with aortic valve regurgitation? Why?
Early decrescendo diastolic murmur
turbulent blood flow across leaky aortic valve in diastole
What are the causes of mitral valve regurgitation?
Myxomatous degeneration
Damage to papillary muscles after MI
Left-sided heart failure
Chronic rheumatic fever
How does myxomatous degeneration lead to mitral valve regurgitation?
Weakens connective tissue, including chordae tendineae
valve prolapses
How does left-sided heart failure lead to mitral valve regurgitation?
LV dilates
pulls apart valve cusps
How does chronic rheumatic fever lead to mitral valve regurgitation?
Inflammation of valve,
fibrosis of valve,
cusps don’t fit together
What is the consequence of mitral valve regurgitation?
LV hypertrophy
How does mitral valve regurgitation lead to LV hypertrophy?
Backflow of blood from LV into LA in systole
means more blood fills the LV in diastole, higher EDV and EDP
becomes stretched
What is the abnormal heart sound with mitral valve regurgitation? Why?
Holosystolic murmur
turbulent blood flow across leaky mitral valve in systole
