Pathoma - Valvular disorders Flashcards
What is the cause/pathogenesis of acute rheumatic fever
Complication of pharyngitis due to group A strep
Due to molecular mimicry of bacterial M protein
Describe the JONES criteria of acute rheumatic fever
J - joints (migratory polyarthritis)
O - heart (pancarditis)
N - subcutaneous nodules
E - erythema marginatum
S - Sydenham chorea
What valve is most commonly affected in acute rheumatic fever
Mitral
Describe endocarditis caused by acute rheumatic fever
Small vegetations along lines of closure of the mitral valve that to regurgitation
Describe the histology of myocarditis of acute rheumatic fever
Aschoff bodies (foci of chronic inflammation, Anitschkow cells, giant cells, and fibrinoid material
What are Anitschkow cells and what disease are they associated with?
Reactive histiocytes with slender, wavy nuclei within Aschoff bodies
Involved in myocarditis caused by Acute Rheumatic fever
What is the consequence of chronic rheumatic heart disease
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)
What is a complication of chronic rheumatic fever
Infectious endocarditis
What are the different effects of chronic and acute rheumatic fever on the mitral valve
Acute - mitral regurgitation (due to vegetation)
Chronic - mitral stenosis (due to scarring)
What is the most common cause of aortic stenosis?
Fibrosis and calcification from “wear and tear”
How do you differentiate aortic stenosis caused by “wear and tear” vs. caused by chronic rheumatic fever
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)
What abnormal heart sound will you hear in aortic stenosis?
Systolic ejection click with crescendo-decrescendo murmur
What are some complications of aortic stenosis?
Concentric LV hypertrophy
Angina and syncope with exercise (stenosis prevents increased blood flow)
Microangiopathic hemolytic anemia (RBCs damaged when crossing calcified valve)
Treatment of aortic valve stenosis
Valve replacement after onset of complications
Causes of aortic regurgitation
Aortic root dilation (e.g. syphilitic aneurysm and aortic dissection)
Valve damage (e.g. infectious endocarditis)
What abnormal heart sound do you hear in aortic regurgitation?
Early, blowing diastolic murmur
What is hyperdynamic circulation and what valve defect is it seen in
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
Treatment of aortic regurgitation
Valve replacement once LV dysfunction develops
What is the cause of mitral prolapse, and what diseases may it be associated with
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
What abnormal heart sound is heard in mitral valve prolapse?
Incidental mid-systolic click (prolapsing valve fully filling) followd by regurgitation murmur
Complications of mitral valve prolapse
Infectious endocarditis
Arrhythmia
Severe mitral regurgitation
Causes of mitral regurgitation
Mitral valve prolapse
LV dilation (pulls apart the valve)
Infective endocarditis
Acute rheumatic heart disease (vs. chronic which will cause stenosis)
What abnormal heart sound will you hear in mitral regurgitation?
Holosystolic “blowing” murmur
Louder with squatting and expiration
Most common cause of mitral valve stenosis
Chronic rheumatic heart disease
