Pathoma - Valvular disorders

Question 1

What is the cause/pathogenesis of acute rheumatic fever

Answer 1

Complication of pharyngitis due to group A strep

Due to molecular mimicry of bacterial M protein

Question 2

Describe the JONES criteria of acute rheumatic fever

Answer 2

J - joints (migratory polyarthritis)

O - heart (pancarditis)

N - subcutaneous nodules

E - erythema marginatum

S - Sydenham chorea

Question 3

What valve is most commonly affected in acute rheumatic fever

Answer 3

Mitral

Question 4

Describe endocarditis caused by acute rheumatic fever

Answer 4

Small vegetations along lines of closure of the mitral valve that to regurgitation

Question 5

Describe the histology of myocarditis of acute rheumatic fever

Answer 5

Aschoff bodies (foci of chronic inflammation, Anitschkow cells, giant cells, and fibrinoid material

Question 6

What are Anitschkow cells and what disease are they associated with?

Answer 6

Reactive histiocytes with slender, wavy nuclei within Aschoff bodies

Involved in myocarditis caused by Acute Rheumatic fever

Question 7

What is the consequence of chronic rheumatic heart disease

Answer 7

Valve scarring (almost always mitral valve, sometimes aorta)

• In mitral valve, leads to thickening of the chordae tendinae and stenosis
• In aorta, results in stenosis with “fish-mouth” appearance (fusion of commissures)

Question 8

What is a complication of chronic rheumatic fever

Answer 8

Infectious endocarditis

Question 9

What are the different effects of chronic and acute rheumatic fever on the mitral valve

Answer 9

Acute - mitral regurgitation (due to vegetation)

Chronic - mitral stenosis (due to scarring)

Question 10

What is the most common cause of aortic stenosis?

Answer 10

Fibrosis and calcification from “wear and tear”

Question 11

How do you differentiate aortic stenosis caused by “wear and tear” vs. caused by chronic rheumatic fever

Answer 11

Chronic rheumatic heart disease:

• Aortic and mitral stenosis
• Aortic stenosis caused by fusion of commissures due to scarring

Wear and tear:

• Only aortic stenosis
• Aortic stenosis caused by vegetations (no fusion)

Question 12

What abnormal heart sound will you hear in aortic stenosis?

Answer 12

Systolic ejection click with crescendo-decrescendo murmur

Question 13

What are some complications of aortic stenosis?

Answer 13

Concentric LV hypertrophy

Angina and syncope with exercise (stenosis prevents increased blood flow)

Microangiopathic hemolytic anemia (RBCs damaged when crossing calcified valve)

Question 14

Treatment of aortic valve stenosis

Answer 14

Valve replacement after onset of complications

Question 15

Causes of aortic regurgitation

Answer 15

Aortic root dilation (e.g. syphilitic aneurysm and aortic dissection)

Valve damage (e.g. infectious endocarditis)

Question 16

What abnormal heart sound do you hear in aortic regurgitation?

Answer 16

Early, blowing diastolic murmur

Question 17

What is hyperdynamic circulation and what valve defect is it seen in

Answer 17

Seen in aortic regurgitation

It is an increase in pulse pressure:

• Diastolic pressure decreases since blood in the aorta flows backwards during diastole
• Systolic pressure increases since there is more blood to eject because of regurg from previous diastole

Presents with bounding pulse, pulsating nail bed, and head bobbing

Question 18

Treatment of aortic regurgitation

Answer 18

Valve replacement once LV dysfunction develops

Question 19

What is the cause of mitral prolapse, and what diseases may it be associated with

Answer 19

Due to myxoid degeneration (connective tissues are replaced by a gelatinous or mucoid substance) of the valve, making it floppy

May be associated with Marfan’s or Ehlers-Danlos

Question 20

What abnormal heart sound is heard in mitral valve prolapse?

Answer 20

Incidental mid-systolic click (prolapsing valve fully filling) followd by regurgitation murmur

Question 21

Complications of mitral valve prolapse

Answer 21

Infectious endocarditis

Arrhythmia

Severe mitral regurgitation

Question 22

Causes of mitral regurgitation

Answer 22

Mitral valve prolapse

LV dilation (pulls apart the valve)

Infective endocarditis

Acute rheumatic heart disease (vs. chronic which will cause stenosis)

Question 23

What abnormal heart sound will you hear in mitral regurgitation?

Answer 23

Holosystolic “blowing” murmur

Louder with squatting and expiration

Question 24

Most common cause of mitral valve stenosis

Answer 24

Chronic rheumatic heart disease

Question 25

What abnormal heart sound will you hear in mitral stenosis?

Answer 25

Opening snap followed by diastolic rumble

Question 26

What are the consequences of LA dilation due to mitral stenosis

Answer 26

Pulmonary congestion (edema and alveolar hemorrhage)

Pulmonary HTN (R-heart failure)

Atrial fibrillation due to LA dilation (risk for mural thrombi)