Cardiac Valve Pathology

Question 1

When do valvular diseases become clinically significant?

Answer 1

when they produce a functional disorder

Question 2

How are valvular diseases broadly classified?

Answer 2

as valvular stenosis or valvular insufficiency

*sometimes both disorders can occur in the same valve.

Question 3

*What is a valvular disorder called if it is seen in one valve?

Answer 3

ISOLATED disease

Question 4

*What is a valvular disorder called if it involves more than one valve?

Answer 4

COMBINED disease

Question 5

What is valvular stenosis?

Answer 5

failure of a valve to open completely, impeding forward flow.

Question 6

What is valvular insufficiency

Answer 6

regurgitation or incompetence, resulting from failure of a valve to close completely, allowing reversed flow.

Question 7

Can you have valvular stenosis and insufficiency occurring together?

Answer 7

YES (can be purely one or the other or may be coexist in the same valve).
*One of the defects usually predominates.

Question 8

What is functional regurgitation?

Answer 8

when a valve becomes incompetent because:

1. dilation of the ventricle causes papillary muscles to be pulled down and outward.
2. dilation of the aorta or pulmonary artery pulls the valve commissures apart, preventing full closure of AV or PV.

Question 9

What dictates the severity of valvular disease?

Answer 9

depends on the valve involved, the degree of impairment, the rate of its development, and the rate of compensatory mechanisms.
It may also produce changes in other organs (heart, blood vessels, or lungs).

Question 10

*What are the most frequent valvular diseases?

Answer 10

stenosis of the AV and MV

Question 11

What usually causes valvular stenosis?

Answer 11

a primary cuspal deformity and is usually chronic

Question 12

What causes valvular insufficiency?

Answer 12

either intrinsic disease of the cusps or damage to or distortion of the supporting structures without primary changes in the cusps.

Question 13

What is calcified valvular degeneration?

Answer 13

valves can suffer cumulative damage with formation of calcium phosphate deposits: calcific aortic stenosis, calcification of bicuspid aortic valve or mitral annular calcification.

Question 14

*What is dystrophic calcification?

Answer 14

normal serum calcium level with calcium deposited on abnormal tissue.

Question 15

*What is metastatic calcification?

Answer 15

calcification occurring due to hypercalcemia.

Question 16

*What is the most common of all valvular abnormalities?

Answer 16

acquired aortic stenosis

Question 17

What is acquired calcific aortic stenosis?

Answer 17

heaped up masses of calcium build up within the aortic cusps preventing opening of the cusps due to age related wear and tear. This may be seen in normal or bicuspid valves.
This becomes symptomatic later in life and as the deposits distort the architecture they can cause LV pressure overload.

Question 18

To what does left ventricular hypertrophy from calcific aortic stenosis lead?

Answer 18

ischemia, angina pectoris, and CHF can occur.

*Pulmonary back flow does not occur in early forms of disease.

Question 19

What can result if the left ventricle begins to fail?

Answer 19

the lungs can become congested and COR PULMONALE can result= abnormal enlargement of the right side of the heart.
Asymptomatic pts have a good prognosis, but symptomatic patients need surgical intervention (valve replacement).
Usually begins with higher pitched murmur.

Question 20

**What is the most frequent CONGENITAL cardiovascular malformation?

Answer 20

BICUSPID aortic valve (cusps usually of unequal size; one cusp usually has a partial fusion). This is generally asymptomatic at birth or early life, but predisposes you to progressive degenerative calcification (usually the larger cusp).

Question 21

What problems can occur with calcific stenosis from congenitally bicuspid AV?

Answer 21

it may become incompetent from aortic dilation, cusp prolapse or infectious endocarditis.

Question 22

What is important to know about mitral annular calcification?

Answer 22

this is when degenerative calcium deposits develop in the fibrous ring of the MV causing irregular hard stony nodules behind the leaflets.
It generally does not affect valvular function, but occasionally can result in REGURGITATION, STENOSIS, ARRHYTHMIA, or SUDDEN DEATH.

Question 23

In whom is mitral annular calcification most seen?

Answer 23

women over 60 and those with mitral valve prolapse or elevated LV pressure.

Question 24

What is myxomatous degeneration of the mitral valve (aka mitral valve prolapse)?

Answer 24

• one or both MV leaflets are floppy and prolapse or balloon into the left atrium.
• Often affects young women.
• Most asymptomatic, but can cause chest pain or syncope.
• Will hear a “midsystolic click”

Question 25

What can happen to the tendinous cords in myxomatous degeneration of the MV?

Answer 25

• Elongate, thin out and may rupture.
• You may also see attenuation of the collagenous fibrosis layer of the valve, with thickened spongiosa layer and deposition of mucoid material making it edematous.

Question 26

What are the secondary changes that can occur with MVP?

Answer 26

fibrous thickening of the valve leaflets and linear fibrous thickening of the LV and/or left atrium endocardial surface.
Thrombotic plaques can form where the valve contacts the atrium.

Question 27

*In what syndrome may you see MVP?

Answer 27

Marfan due to mutations in fibrillin-1 gene, which dysregulates TGF-beta signaling.

Question 28

What does MVP actually look like grossly?

Answer 28

a parachute or “hooding” of the mitral valve.

Question 29

What are some complications that can occur with MVP?

Answer 29

infectious endocarditis, chordal rupture, emboli, arrhythmias…

Question 30

**What is acute rheumatic fever?

Answer 30

systemic complication of pharyngitis due to GROUP A beta-hemolytic streptococci; affects children 2-3 weeks after an episode of streptococcal pharyngitis (step throat).
It is an immunologically mediated inflammatory disease. The bacteria initiate an IMMUNE REACTION, and these ANTIBODIES cross-react with glycoproteins on the heart valve and joints.

Question 31

What will you see clinically with rheumatic fever?

Answer 31

elevated ASO (antistreptolysin-O) or anti-DNase B titers

Question 32

What does rheumatic fever usually do to the mitral valve?

Answer 32

forms fibrotic disease (mitral stenosis). More commonly seen in areas of the world without access to antibiotics.

Question 33

What are the MAJOR criteria for diagnosing acute rheumatic fever?

Answer 33

1. migratory polyarthritis= swelling and pain in a large joint that resolves within days and migrates to inovled another large joint.
2. Pancarditits= all 3 layers: endocarditis (small vegetations along the lines of closure), myocarditits with Aschoff bodies, and pericarditits.
3. subcutatneous nodules
4. erythema marginatum= annular nonpruritic rash with erythematous borders.
5. Sydenham chorea= rapid involuntary muscle movements.

Question 34

**What are Aschoff bodies?

Answer 34

fibrinoid necrosis of the MYOCARDIUM surrounded by chronic mononuclear cell inflammation, associated with acute rheumatic carditis.
Within these you will see ANITSCHKOW CELLS= large histiocytes with vesicular nuclei and basophilic cytoplasm (they have an owl-eye appearance in cross-section and caterpillar appearance in longitudinal sections).

Question 35

What can fibrinous pericarditis of acute rheumatic fever cause?

Answer 35

a friction rub heard on auscultation

Question 36

Can calcium nodules develop on valves in acute rheumatic carditis?

Answer 36

YES, distorting the valve and can form thrombi.

Question 37

Can you develop right sided heart failure with acute rheumatic fever?

Answer 37

YES and liver congestion.

Question 38

**What are MacCallum plaques?

Answer 38

subendocardial lesions that produce irregular thickenings (usually in the left atrium) associated with rheumatic fever.

Question 39

**What is the trick to remembering clinical rheumatic fever?

Answer 39

STREP:
Sydenham's chorea
Transitory migratory arthritis
Rheumatic subcutaneous nodules
Erythema marginatum
Pancarditis

Question 40

What is the Jones criteria of rheumatic fever?

Answer 40

1. evidence of prior group A streptococcal pharyngitis.
2. presence of 2 of the major manifestations or presence of 1 major and 2 minor manifestation such as fever, arthralgias, or elevated blood levels of acute phase reactants or ESR.

Question 41

When do heart abnormalities associated with acute rheumatic fever occur after an episode of pharyngitis?

Answer 41

10 days to 6 weeks, occurring more in children ages 5-15.

Question 42

**What changes of the valve are associated with acute vs. chronic rheumatic heart disease?

Answer 42

acute= vegetations along the LINES OF CLOSURE.
chronic= fibrous thickening and fusion of the chordae tendinae.

Question 43

To what does chronic rheumatic heart disease lead?

Answer 43

stenosis of the mitral valve and occasionally the aortic valve with a classic “fish-mouth appearance.”

Question 44

What is the most common cause of mitral stenosis?

Answer 44

mitral valvulitis from CHRONIC rheumatic heart disease

Question 45

**What will you see on the valves in chronic rheumatic heart disease?

Answer 45

increased vascularity with focal lymphocytic infiltrates.

Question 46

What commonly happens to the left atrium in chronic rheumatic heart disease?

Answer 46

it becomes dilated and hypertrophied

Question 47

Does vulnerability for rheumatic fever increase after an initial attack?

Answer 47

YES. About 1% die, and damage to the valves is cumulative.

Question 48

Are Aschoff bodies seen in CHRONIC rheumatic fever?

Answer 48

NO, only acute.

Question 49

What is chronic aortic valvulitis?

Answer 49

aortic stenosis (valve cusps thick, firm and adherent to one another) leading to LVH or aortic regurg (fibrosis and retraction), and unlike rheumatic fever, this occurs more in men.