Cardiac: Vavlular Disorders Flashcards
valvular lesions generally result in either what 2 things
- stenosis
2. regurgitation
what causes acute rheumatic fever
- systemic complication of pharyngitis due to group A beta-hemolytic streptococci
- step bacteria M protein resembles human tissue
- molecular mimicry
who usually gets acute rheumatic fever
children 2-3 weeks after an episode of streptococcal pharyngitis (“strep throat”)
What are 3 categories for a diagnosis of acute rheumatic fever
- prior group A beta-hemolytic strep infection
- fever and elevated ESR
- JONES criteria
ESR
erythrocyte sedimentation rate
what is the JONES criteria
Joints: migratory polyarthritis Heart: panarditis ( all 3 layers of heart) Subcutaneous Nodules Erythema marginatum Sydenham chorea
what is sydenham chorea
rapid, involuntary muscle movements
what is erythema marginatum? what area of the body does this usually impact?
annular, nonpruritic rash with erythematous borders, commonly involving trunk and limbs
where can pancarditis occur
- endocarditis
- myocarditis
- pericarditis
what characterizes the endocarditis? what does it lead to? what valves are involved?
- small vegetations along lines of closure that lead to regurgitation
- mitral more commonly involved than aortic
what characterizes myocarditis
Aschoff bodies with foci of chronic inflammation, reactive histocytes with slender, wavy nuclei ( Anitschkow cells) , giant cells, fibrinoid material
what is the most common cause of death during the acute phase rheumatic fever
myocarditis
how does pericarditis present clinically
friction rub and chest pain
having relapse of acute rheumatic fever increases the chances of what
chronic rheumatic fever
what is chronic rheumatic heart disease
valve scarring as a consequence of rheumatic fever
chronic rheumatic heart disease results in what
stenosis with classic ‘fish-mouth’ apperance
what valve is usually involved in chronic rheumatic fever
- most common is mitral valve: thickening of chordae tendineae and cusps
- occasionally aortic valve: fusion of commissures
what is a complication with chronic rheumatic heart disease
endocarditis
what is aortic stenosis
narrowing of aortic valve oriface
what can cause aortic stenosis
- fibrosis and calcification “wear and tear”
2. chronic rheumatic valve disease
who does ‘wear and tear’ aortic stenosis usually occur in?
late adulthood, greater than 60
what type of valve can lead to aortic stenosis
bicuspid aortic valve
what distinguishes ‘wear and tear’ aortic stenosis from chronic rheumatic valve aortic stenosis
- coexisting mitral stenosis and fusion of aortic valve commissures distinguish rheumatic disease from ‘wear and tear’
cardiac compensation from aortic stenosis leads to what
prolonged asymptomatic stage: systolic ejection click followed by crescendo-decrescendo murmur is heard
what are 3 complications with aortic stenosis
- concentric left ventricular hypertrophy
- angina and syncope with exercise
- microangiopathic hemolytic anemia
having concentric left ventricular hypertrophy can lead to what
cardiac failure
why does angina and syncope with exercise occur with aortic stenosis
limited ability to increase blood flow across the stenotic valve leads to decreased perfusion of the myocardium and brain
what happens in microangiopathic hemolytic anemia
RBCs damaged producing schistocytes while crossing calcified valve
what is the treatment for aortic stenosis
valve replacement after onset of complications
what is aortic regurgitation
- backflow of blood from aorta into left ventricle during diastole
what are causes of aortic regurgitation
- aortic root dilation - syphilitic aneurysm and aortic dissection
- valve damage - infectious endocarditis
what is the most common cause of aortic regurgitation
isolated root dilation
what are 3 clinical features of aortic regurgitation
- early, blowing diastolic murmur
- hyperdynamic ciruclation
- LV dilation and eccentric hypertrophy (increase preload)
how does hyperdynamic circulation occur
- increase pulse pressure ( difference in systolic and diastolic pressure)
- diastolic pressure decreases due to pressure regurgitation
- systolic pressure increases due to increase stroke volume
what clinical sytmptoms does hyperdynamic circulation occur in aortic regurgitiaton
- bounding pulse (water-hammer pulse)
- pulsating nail bed (Quincke pulse)
- head bobbing
what is the treatment for aortic regurgitaion
valve replacement once LV dysfunction develops
what is mitral valve prolapse
ballooning of mitral valve into left atrium during systole
what specifically happens to the valve in mitral valve prolapse
myxoid degeneration (accumulation of ground substance) , makeing valve floppy
in what diseases can mitral valve prolapse occur in?
Marfan syndrome
Ehlers-Danlos syndrome
clinically how does mitral valve prolapse show up as
incidental mid-systolic click (followed by a regurgitation murmur; usually asymptomatic)
correlate click and murmurs with squatting
click and murmur become softer with squatting ( increased systemic resistance decreases left ventricular emptying)
What are complications of mitral valve prolapse complications
rare but can include
- infectious endocarditis
- acute rheumatic heart disease
- papillary muscle rupture after a myocardial infarction
what is the treatment for mitral valve prolapse
valve replacement
what is mitral regurgitation
reflux of blood from left ventricle into left atrium during systole
what complications can cause mitral regurgitation
- mitral valve prolapse
- LV dilation (Left-sided cardiac failure)
- infective endocarditis
- acute rheumatic heart disease
- papillary muscle rupture after myocardial infarction
what are 2 clinical features of mitral regurgitation
- Holosystoilc “blowing” murmur
2. volume overload and left-sided heart failure
how does squatting and expiration impact mitral regurgitation
squatting: increased systemic resistance decreases left ventricular emptying
expiration: increased return to left atrium
what is mitral stenosis
narrowing of mitral valve oriface
clinical features of mitral stenosis
- opening snap followed by diastolic rumble
2. volume overload
Volume overload from mitral stenosis causes what
dilatation of left atrium resulting in
- pulmonary congestion with edema and alveolar hemorrhage
- pulmonary hypertension and eventual right-sided heart failure
- atrial fibrillation with associated risk for mural thrombi
