Valvular Disorders Flashcards
Acute Rheumatic Fever
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
what is the jones criteria for Acute Rheumatic Fever?
- Migratory Polyarthritis
- Pancarditis (Endo, Myo, Pericarditis)
- Subcutaneous nodules
- Erythema marginatum
- Sydenham chorea
what is the most common valve involved in acute rheumatic fever
mitral valve then aortic valve: regurgitation–>Endocarditis
myocarditis usually presents with
Anitschkow cells, giant cells, fibrinoid material
aschoff bodies characterized by foci of chronic inflammation, reactive histiocytes with slender, wavy nuclei
most common cause of death during the acute phase
is in myocarditis
Pericarditis leads to
friction rub and chest pain
what increases the risk of chronic disease
repeat exposure to group A Beta hemolytic streptococci results in relapse of the acute phase and increases risk for chronic disease
what is a consequence of chronic rhematic fever?
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
aortic stenosis
- due to fibrosis and calcification from wear and tear
- Patient presentation: in late adulthood (>60 years)
how many valves does the aorta normally have and what happens if there is less
normally tricuspid, but if biscuspid then there is increase risk and disease onset is hastened. Increased wear and tear
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
coesixting mitral stenosis and fusion of the aortic valve commissures distinguish rheumatic disease from wear and tear
hallmark of aortic stenosis
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
what are the complications of aortic stenosis?
- 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
treatment of aortic stenosis is
valve replacement after onset of complications
most common cause for an aortic regurgitation
aortic root dilation (e.g during syphilitic aneurysm) or valve damage (i.e infectious endocarditis)
what are the clinical features of Aortic regurgitation?
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()
in aortic regurgitation what happens to the Diatolic and systolic pressure
Diastolic pressure decreases due to regurgitation, while systolic pressure increases due to increased stroke volume
mitral valve prolapse
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
Describe the mid systolic click in response to squatting
it becomes softer with squatting because of increased systemic resistance decreasing left ventricular emptying
what are the complications of mitral valve prolapse
complications are rare, but include infectious endocarditis, arrhythmia, and severe mitral regurgitation
mitral regurgitation
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
what are the clinical features of mitral regurgitation
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
mitral valve stenosis
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
what does the dilatation of the left atrium in mitral stenosis lead to
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
