12.5 A Flashcards
What is valvular stenosis?
the failure of a valve to open completely
What is valvular insufficiency?
failure of a valve to close completely, thereby allowing reversed flow
What is functional regurgitation?
the incompetence of a valve stemming from an abnormality in one of its support structures
Functional regurgitation could be thought of as a ____ valve defect.
secondary
What is mixed valvular stenosis?
stenosis with regurgitation
What is combined valvular stenosis?
involvement of more than one valve
The most frequent cause of aortic stenosis is what?
dystrophic calcification of an anatomically normal or congenitally bicuspid aortic valve
The most frequent cause of aortic insufficiency is what?
dilation of the ascending aorta related to hypertension, atherosclerosis, or aging
The most common cause of mitral stenosis is what?
rheumatic heart disease
The most common cause of mitral insufficiency is what?
myxomatous degeneration (prolapse)
Infective endocarditis can cause what valvular heart disease?
mitral or aortic regurgitation
What is the most common of all valvular abnormalities?
calcific aortic stenosis
The typical age of onset for aortic valvular stenosis of an anatomically normal valve is what?
60-80
The typical age of onset for aortic valvular stenosis of a bicuspid aortic valve is what?
40-60
Bicuspid aortic valves likely experience stenosis early because…
they incur more mechanical stress than normal tricuspid valves
Rheumatic aortic differs from calcific aortic stenosis with regards to what morphological feature?
rheumatic aortic stenosis often has a commissural fusion
Aortic stenosis leads to what other complication related to the pressure build up it incites?
left ventricular hypertrophy
Myxomatous degeneration is associated with what valvular heart disease?
mitral valve prolapse
How is mitral valve prolapse typically treated?
- it is usually asymptomatic
- anti-microbial prophylaxis is recommended during dental procedures to prevent endocarditis
Mitral valve prolapse has what symptoms and complications?
usually asymptomatic although there is a slightly increased risk of sudden death due to arrhythmia
Mitral valve prolapse puts one at greater risk for endocarditis because of what?
because flow is abnormal, creating eddies that lead to fibrin deposition and that fibrin is capable of catching bacteria in the blood stream
Rheumatic fever can follow what sort of infection?
group A streptococci
Describe the pathogenesis of rheumatic fever?
- group A streptococci infection
- molecular mimicry results in cross reaction to myocardial tissue
- chronic inflammatory response to myocardial tissue
- deformity and damage
Sydenham’s chorea is a diagnostic feature of what disease?
rheumatic fever
What are aschoff bodies?
distinctive lesions in the heart of those suffering from rheumatic fever
What are anitschkow cells?
large histiocytes with abundant basophilic cytoplasm that are part of aschoff bodies
Describe aschoff bodies
distinct foci of fibrinoid necorsis surrounded by lymphocytes and macrophages
Describe the joint involvement of rheumatic fever.
acute, non-specific, migratory arthritis, especially in the knees
Describe the skin involvement of rheumatic fever.
subcutaneous nodules or erythema marginatum
What are erythema marginatum?
giant aschoff bodies presenting as a rash in rheumatic fever patients
Rheumatic fever affects what systems?
- heart
- joints
- skin
- arteries
How does rheumatic fever affect the arteries?
hypersensitivity angitis
What are the cardinal anatomic changes of the mitral valve in rheumatic heart disease?
- leaflet thickening
- commissural fusion and shortening
- thickening and fusion of the tendinous cords
What are the features of rheumatic heart disease?
- pulmonary congestion andedema
- hemorrhage and infarction
- hyperplasia of pulmonary arteries
- hemosiderosis
- fibrosis of alveolar septa
- right-sided heart failure
What are the two categories of infective endocarditis?
acute and sub-acute
What are some major risk factors for infective endocarditis?
- drug use
- artificial valves
- valvular dysfunction
- rheumatic heart disease
What is acute versus sub-acute endocarditis?
- acute is typically caused by infection of a previously normal heart valve by a highly virulent organism
- sub-acute is caused by less virulent organisms and cause infections of deformed valves that are less destructive
What are the clinical criteria for infective endocarditis?
- positive blood cultures
- EKG findings
- new valvular regurgitation or murmur
Which organism is most commonly implicated in acute infective endocarditis?
staph aureus
What is the HACEK group?
a group of bacteria known to cause endocarditis
What is a ring abscess?
the abscess created by endocarditis vegetations eroding the underlying myocardium
What are Osler nodes?
subcutaneous nodules in the pulp of the digits seen in endocarditis
What are Janeway lesions?
erythematous or hemorrhagic non-tender lesions on the palms or soles seen in endocarditis
What are Roth spots?
retinal hemorrhages seen in endocarditis
The most common contaminant of blood cultures is what organism?
coag-neg Staph
The most common reason for blood culture contamination is what?
failure to adequately decontaminate the skin
Describe the vegetations seen in endocarditis.
fibrin, inflammatory cells, and bacteria
Endocarditis most commonly affects what valves?
aortic and mitral
Septic emboli result from what heart disease?
endocarditis
What is the viridans group?
a group of low virulence strep that are known to cause aub-acute endocarditis
What are the cardiac complications of infectious endocarditis?
- valvular insufficiency or stenosis
- myocardial abscess with possible wall perforation
- suppurative pericarditis
- dehiscence of an artificial valve
Left sided endocarditis lesions are more likely to cause what embolic complications?
systemic embolism in the brain, spleen kidney, etc.
Right sided endocarditis lesions are more likely to cause what embolic complications?
- osler’ nodes
- janeway lesions
- roth spots
- lung involvement
What is non-bacterial thrombotic endocarditis?
- involves the precipitation of small amounts of fibrin and other blood components on the valve leaflets
- vegetations are sterile
Non-bacterial thrombotic endocarditis is most common in what sorts of individuals?
debilitated ones with cancer or sepsis; those with hypercoagulable states
When you see endocarditis vegetations on the underside of a valve, your first thought should be what?
lupus
