4. Valvular Heart Disease

Question 1

Valves of the heart

Answer 1

Have sets of leaflets/cusps

Mitral = 3 cusps others have 3

Mitral and tricuspid valves connected to papillary muscles by tendionous cords

Contraction of papillary muscles opens valves

Question 2

Stenotic

Answer 2

Pressure overload and cardiac hypertrophy

Forces blood back up into adjacent chamber

Too narrow and hardened to open fully

Question 3

Regurgitant

Answer 3

Volume overload = valve prolapse

Allows blood to leak back into chamber it previously exited = unable to close completely

Question 4

Aortic valve sclerosis

Answer 4

Aortic valve thickening (sclerosis) without stenosis

Common in elderly

Can progress to aortic stenosis and is a marker for increased cardiovascular risk

Question 5

Pathogenesis of aortic sclerosis and early calcification aortic valve disease

Answer 5

1. Early initiation phase: lipid accumulation, inflammation, calcification
2. Later propagation phase: more advanced aortic stenosis, calcification more prominent, progressive stiffness, narrowing of valve

Question 6

Aortic stenosis

Answer 6

Aortic valve thickening and calcification without a significant pressure gradient

Etiology: congenital, calcification

Question 7

Acute aortic regurgitation

Answer 7

Usually a medical emergency since L ventricle cannot Quickly adapt to increase in EDV- decrease in cardiac output

Etiology:
Endocarditis: causes valve destruction and leaflet perforation

Question 8

Chronic aortic regurgitation

Answer 8

The volume overload of the LV causes an increase in LV size that - a normal cardiac output regardless of regurgitation

Question 9

Mitral stenosis

Answer 9

Thickening and immobility of mitral leaflets

Etiology: rheumatic heart disease

Clinical sequeale:
Obstruction of blood flow from L atrium to L ventricle
Increased pressure within:
L atrium = LA dilation, Afib, LA thrombosis
Pulmonary vasculature = medial hypertrophy
R side of heart = RV dilation

Question 10

Rheumatic heart disease

Answer 10

Result of an exaggerated immune response to specific bacteria in a susceptible host

Cross-reactivity between streptococcal antigen and valve tissue - inflammation in valve leaflets

Question 11

Mitral valve prolapse

Answer 11

Most common cause of chronic mitral regurgitation

Thickening and degeneration of leaflets and chordae

Pathology:
CT abnormalities
Hallmark is excessive mitral leaflet that causes folding and hooding
Blood leaks back into L atrium