Valvular Disorders

Question 1

Acute Rheumatic Fever

Answer 1

A group A B-hemolytic streptococci

affects children 2-3 weeks after an episode of streptococcal pharyngitis (“strep throat”)

Molecular mimicry; bacterial M protein resembles proteins in human tissue

Question 2

what is the jones criteria for Acute Rheumatic Fever?

Answer 2

• Migratory Polyarthritis
• Pancarditis (Endo, Myo, Pericarditis)
• Subcutaneous nodules
• Erythema marginatum
• Sydenham chorea

Question 3

what is the most common valve involved in acute rheumatic fever

Answer 3

mitral valve then aortic valve: regurgitation–>Endocarditis

Question 4

myocarditis usually presents with

Answer 4

Anitschkow cells, giant cells, fibrinoid material

aschoff bodies characterized by foci of chronic inflammation, reactive histiocytes with slender, wavy nuclei

Question 5

most common cause of death during the acute phase

Answer 5

is in myocarditis

Question 6

Pericarditis leads to

Answer 6

friction rub and chest pain

Question 7

what increases the risk of chronic disease

Answer 7

repeat exposure to group A Beta hemolytic streptococci results in relapse of the acute phase and increases risk for chronic disease

Question 8

what is a consequence of chronic rhematic fever?

Answer 8

valve scarring- mitral valve stenosis almost always and leads to thickening of chordae tendineae and cusps

could involve the aortic valve, leading to fusion of the commissures

and the complication is endocarditis

Question 9

aortic stenosis

Answer 9

• due to fibrosis and calcification from wear and tear
• Patient presentation: in late adulthood (>60 years)

Question 10

how many valves does the aorta normally have and what happens if there is less

Answer 10

normally tricuspid, but if biscuspid then there is increase risk and disease onset is hastened. Increased wear and tear

Question 11

since aortic stenosis may also arise from chronic rheumatic fever, how can you distinguish it from the aortic stenosis that occurs with wear and tear

Answer 11

coesixting mitral stenosis and fusion of the aortic valve commissures distinguish rheumatic disease from wear and tear

Question 12

hallmark of aortic stenosis

Answer 12

cardiac compensation leads to a prolonged asymptomatic stage during which a systolic ejection click followed by a crescendo-decrescendo murmur is heard

systolic ejection click-abrupt haulting of the valve leaflet

Question 13

what are the complications of aortic stenosis?

Answer 13

• concentric left ventricular hypertrophy- may progress to cardiac failure
• angina and syncope with exercise- limited ability to increase blood flow across the stenotic valve leads to decreased perfusion of the myocardium and brain
• microangiopathi hemolytic anemia-RBCs are damaged (producing schitocytes) while crossing the calcified valve

Question 14

treatment of aortic stenosis is

Answer 14

valve replacement after onset of complications

Question 15

most common cause for an aortic regurgitation

Answer 15

aortic root dilation (e.g during syphilitic aneurysm) or valve damage (i.e infectious endocarditis)

Question 16

what are the clinical features of Aortic regurgitation?

Answer 16

Early blowing diastolic murmur

hyperdynamic circulation due to inc pulse pressure(diference between systolic and diastolic pressures)

Presents with bounding pulse (water-hammer pulse), pulsating nail bed(quincke pulse), head bobbing

LV dilation and eccentric hypertrophy (due to volume overload()

Question 17

in aortic regurgitation what happens to the Diatolic and systolic pressure

Answer 17

Diastolic pressure decreases due to regurgitation, while systolic pressure increases due to increased stroke volume

Question 18

mitral valve prolapse

Answer 18

occurs during systole

due to myxoid degeneration (accumulation of ground substance) of the valve, making it floppy

Seen in Marfan syndrome or Ehlers-Danlos syndrome

Presentation is incidental mid-systolic click followed by a regurgitation murmur; usually asymptomatic

Question 19

Describe the mid systolic click in response to squatting

Answer 19

it becomes softer with squatting because of increased systemic resistance decreasing left ventricular emptying

Question 20

what are the complications of mitral valve prolapse

Answer 20

complications are rare, but include infectious endocarditis, arrhythmia, and severe mitral regurgitation

Question 21

mitral regurgitation

Answer 21

arises as a complication of mitral valve prolapse; other causes include LV dilatation (left-sided cardiac failure), infective endocarditis, acute rheumatic heart disease, and papillary muscle rupture after a myocardial infarction

Question 22

what are the clinical features of mitral regurgitation

Answer 22

holosystolic blowing murmur; louder with squatting (increased systemic resistance decreases left ventricular emptying) and expiration (increased return to left atrium)

Results in volume overload and left-sided heart failuree

Question 23

mitral valve stenosis

Answer 23

narrowing of the mitral valve orifice

due to chronic rheumatic valve disease

Clinical features: -opening snap followed by diastolic rumble

-volume overload leads to dilatation of the left atrium

Question 24

what does the dilatation of the left atrium in mitral stenosis lead to

Answer 24

it leads to pulmonary congestion with edema and alvolar hemorrhage

pulmonary hypertension and eventual right sided heart failure

atrial fibrillation with associated risk for mural thrombi

Question 25

what are the anatomic impacts of stenosis in mitral and aortic stenosis?

Answer 25

Left Atrium Dilatation in mitral stenosis and left ventricular hypertrophy in aortic stenosis

Question 26

Case of a person with mitral valve stenosis

Answer 26

patient can present with:

1. Hoarse voice: LA dilates and impinges on the recurrent laryngeal nerve (LA is a posterior structure that is directly in front of the nerve and esophagus)
2. Hemoptysis, dyspnea on exertion and paroxysmal nocturnal dyspnea: due to pulmonary edema because of increased LA pressure
3. Can be associated with rheumatic fever
4. Loud S1, Loud P2, Rumbling mid-diastolic murmur and an opening snap