Lecture 15 - CV III (Cardiac Valvular Disease and Vasculitis) Flashcards
What is mitral valve stenosis?
Acquired stenosis (failure of a valve to open completely, obstructing forward flow) is usually due to chronic (recurrent) rheumatic valvular disease)
What disease is described:
Systemic disease, usually in children
-follows a group A beta-hemolytic streptococcal pharyngitis
acute rheumatic fever
What are some manifestations that acute rheumatic fever (RF) produces?
- myocarditis
- pericarditis
- arthralgia
- arthritis
The myocarditis associated with mitral valve stenosis is characterized microscopically by what?
Aschoff bodies
What are Aschoff bodies?
- collections of mononuclear inflammatory cells and fibroblasts (essentially granulomatous inflammation)
- Found in myocarditis
Recurrent bouts of rheumatic fever eventually lead to what?
-severe fibrosis and calcification of the mitral valve and possibly other heart valves
acute rheumatic fever is thought to be due to what?
production of antibodies against the streptococcal bacteria which cross react with various antigens in the heart, joints, and other sites
In terms of the heart what is meant by regurgitation?
- insufficiency
- a valve that fails to close completely, allowing backflow of blood
What two conditions specifically can cause mitral valve regurgitation?
IHD (ischemic heart disease)
endocarditis
What is mitral valve prolapse?
a condition in which the leaflets ballon into the left atrium during left ventricular contraction (systole)
If mild prolapse common and what percent of the general population does it occur?
mild prolapse is VERY common and occurs in 5-10% of the general population
True/ False: Mild prolapse usually progresses to valvular regurgitation
False:
Mild prolapse usually does NOT progress to valvular regurgitation
Severe prolapse may be associated with what?
valvular regurgitation
What are two side effects that patients with mitral valve regurgitation may experience?
chest pain and palpitations
What are some potential complications of mitral valve regurgitation?
- endocarditis
- mitral regurgitation
- thromboemboli
- sudden death (rare)
what is another name for severe prolapse?
floppy mitral valve
what is found in severe prolapse?
the valve cusps are large and microscopically show fragmentation, separation and loss of collagen (myxomatous degeneration)
Floppy mitral valve (or severe prolapse) may be an isolated abnormality or part of a systemic connective tissue disorder such as what?
Marfan syndrome
in aortic valve stenosis, what two things specifically can reduce the valve cusp mobility?
fibrosis and calcification
What are causes of aortic valve stenosis?
- chronic rheumatic valvular disease
2. advanced age (over 65 years)
when a patient has chronic rheumatic valvular disease the mitral valve is almost always _____
stenotic
What is described: common congenital malformation and these valves are predisposed to calcification and fibrosis beginning at about 40 years of age
bicuspid aortic valve
What are the three mechanisms of aortic valve regurgitation?
- valve cusp destruction (endocarditis)
- myxomatous degeneration
- dilation of the aortic root
infective endocarditis is usually cause by what?
BACTERIAL infection in a heart valve
*Although it may also be cause by fungus or other unusual infections
What are the predisposing factors of infective endocarditis? (6 of them)
- abnormal heart valves
- prosthetic valves
- intravenous drug use
- intracardiac shunts
- diabetes
- immunosuppression
The three factors that have been identified as having importance in the pathogenesis of infective endocarditis include:
- endocardial or endothelial injury due to abnormalities in blood flow
- Fibrin thrombi
- organisms in the blood
What are the clinical manifestations of infective endocarditis?
- Fever
- Heart murmur
- Fatigue
- Anemia
- Arthralgia
- Myalgia
- Splinter hemorrhages (nail bed)
- Roth spots (retinal hemorrhages, not absolutely specific to IE)
what are the complications of infective endocarditis? (5 of them)
- rupture of chordae tendinaea
- Spread of infection into myocardium or aorta
- Thromboembolism with infarction
- Septic thrombi with metastatic abscesses
- valvular dysfunction and CHF
which has a longer duration, acute or subacute endocarditis?
Subacute endocarditis has a longer duration
Acute endocarditis has a short duration
is virulent organism associated with acute or subacute endocarditis?
acute
what is the virulent organisms for acute endocarditis and what is the low virulent organism of subacute endocarditis?
acute endocarditis: staphylococcus aureus
subacute endocarditis: streptococcus viridans
Does acute endocarditis have large friable or small vegetations?
acute: large friable vegetations
subacute: small vegetations
There was a previously normal valve in acute or subacute endocardidits?
acute endocardidits has a previously normal valve
(T/F) Subacute endocarditis has a previously normal valve
FALSE - subacute endocarditis had a previously ABnormal valve
Does acute or subacute endocarditis has more prominent tissue destruction?
acute endocarditis has more prominent tissue destruction
What is the main cause of vasculitis?
-Infection (usually due to direct spread of an adjacent infection; some microorganisms infect endothelial cells and cause vasculitis)
What are some other causes of vasculitis?
- mechanical trauma
- toxins
- caustic substances
- radiation
- immune complexes
what are two examples of large vessel vasculitis?
- giant cell (temporal) arteritis
2. Takayasu arteritis
what are two examples of medium vessel vasculitis?
- Polyarteritis nodosa (classic)
2. Kawaski syndrome
what are two examples of small vessel vasculitis?
- microscopic polyarteritis
2. Wegener’s granulomatosis
in the pathogenesis of immune mediated vasculitis, the immune complex formation is from reaction to what?
drugs or viruses
in the pathogenesis of immune mediated vasculitis, antineutrophilic cytoplasmic antibodies (ANCA) what are the two subtypes?
- Anti-myeloperoxidase (anti-MPO) - perinuclear localization (formerly known as pANCA) - microscopic polyarteritis
- Anti-proteinase-3 (anti-PR3) - diffuse cytoplasmic distribution (formerly known as cANCA) - Wegener’s granulomatosis
in the pathogenesis of immune mediated vasculitis, anti-endothelial cell antibodies are associated wth what disease?
Kawasaki disease
____ - mediated immunity is associated with pathogenesis of immune mediated vasculitis
cell-mediated immunity
What is the etiology of giant cell (temporal) arteritis?
unknown
maybe T cell mediated
what are the clinical findings of giant cell (temporal) arteritis?
- Fever
- Weight loss
- headache
- visual problems (including blindness)
- claudication of jaw (weakness when chewing due to decreased blood supply)
- pain and tenderness over temporal artery
- polymyalgia rheumatica (inflammatory disorder that causes muscle pain and stiffness)
(T/F) giant cell (temporal) arteritis is typially seen in younger individuals
FALSE giant cell (temporal) arteritis is rare under the age of 50 years
what is the pathology of giant cell (temporal) arteritis?
granulomatous inflammation with giant cells, fibrosis
*Eventually causes narrowing of vessel lumen, with decreased blood flow to affected tissues
what is the etiology of Takayasu arteritis?
unknown
what are the clinical findings in Takayasu arteritis?
Thickening of the wall reduced blood flow in the major branches off the aortic arch
what condition is also known as “pulseless disease” due to weak pulses in the arms
Takayasu arteritis
Takayasu arteritis usually affects what population?
young women
may be the same disease as temporal arteritis, but in a younger patient
what is the pathology of Takayasu arteritis?
granulomatous inflammation with fibrosis involving the aortic arch and the arch branches
What disease is unknown in most cases, once up to 30% has hepatitis B surface antigen in the serum, now less than 8% due to widespread immuniations
polyarteritis nodosa
what are some clinical manifestations of polyarteritis nodosa?
- Fever
- Weight loss
- Hematuria
- Renal failure
- Hypertension
- Abdominal pain
- Melana (bloody diarrhea)
*Clinical presentation may be very confusing due to involvement of multiple organ systems
What pathology is described: Haphazard and segmental involvement of medium and small muscular arteries. Acute lesions show fibrinoid necrosis, thrombosis, neutrophils, aneurysms.
polyarteritis nodosa
with healing of polyarteritis nodosa there is predominance of what and progressive fibrous _____?
macrophages and plasma cells and progressive fibrous scarring
in the order of most sites of involvement to least what are the most usual sites of involvement in polyarteritis nodosa?
Kidneys (85%)
Heart (75%)
Liver (65%)
GI tract (50%)
what is the etiology of Kawasaki disease?
viral infection triggers a hypersensitive reaction
AKA: mucocutaneous lymph node syndrome
Kawasaki disease normally affects what population and 80% of patient are less than what age?
African infants and young children
80% of patients are less than 4 years
what are some of the clinical manifestations of Kawasaki disease?
- skin rash
- mucous membrane lesions
- cervical lymphadenopathy
Kawasaki disease is usually self limited, but 1-2% die with because of what?
coronary artery vasculitis
what is the etiology of microscopic polyangitis?
often due to antigen-antibody complexes
what are the clinical manifestations of microscopic polyangitis?
- fever
- rash
- joint swelling
- pleural effusion
- pulmonary infilitrates
- myocarditis
- GI bledding
- renal failure
- presence of circulating anti-neutrophilic cytoplasmia antibodies (MPO-ANCA)
microscopic polyangitis may be precipitated by what?
- Drugs
- Microorganisms
- Foreign proteins
- Tumor proteins
what is the pathology of microscopic polyangitis?
involves arterioles, capillaries, venules
Fibrinoid necrosis, neutrophils (leukocytoclasic vasculitis)
What etiology is described: abnormal expression of proteinase 3 on endothelial cell surface, followed by ANCA binding and neutrophil activation, resulting in damage to endothelium and vessel
Wegener granulomatosis
what are the clinical manifestations of Wegener granulomatosis?
- involves sinuses
- lungs and kidneys (glomerulonephritis)
Wegener granulomatosis is - Associated with the presence of what?
anti-neutrophilic cytoplasmic antibodies direct against proteinase 3 (PR3-ANCA)
what vasculitis condition has the pathology of necrotizing granulomas with vasculitis
wegener granulomatosis
thromboangiitis obliterans as also known as what?
Buerger disease
in thromboangiitis obliterans (Buerger disease) it results from ENDOthelial injury from a substance in what?
cigarette smoke
What are the clinical findings of thromboangiitis?
pain and ischemia in extremities
thromboangiitis usually begins around what age
before age 35
what is the pathology of thromboangiitis obliterans?
segmental acute and chronic vasculitis mainly in extremities with thrombosis
in an aortic hematoma (aneurysn) it begins in the ______ ______ and extends variable distance proximal (toward the heart) and distal to the ____ _____
begins in ASCENDING AORTA and extends variable distance proximal (toward the heart) and distal to the DESCENDING AORTA
what are some complications of a dissecting aortic hematoma (aneurysm)
- severe hemorrhage from rupture
- organ ischemia due to luminal compression by the expanding hematoma
what are the predisposing factors of dissecting aortic hematoma (aneurysm)?
- hypertension
- inherited connective tissue (i.e. Marfan’s syndrome) with medial degeneration
Repeated episodes of acute rheumatic fever can cause what?
mitral valve fibrosis and calcification with valvular stenosis
what is the histopathologic feature of severe mitral valve prolapse (floppy mitral valve)?
myxomatous degeneration
what are the ANCA-positive forms of vasculitis?
Wegener’s granulomatosis and microscopic polyarteritis
what are the complications of dissecting hematoma (split (hematoma) in the media)?
-hemorrhage and branch obstruction
