CPC 4

Question 1

Define stenosis and insufficiency. Which is more likely to present accutely?

Answer 1

failure of the valve to open completely, impedes forward flow

insufficiency results from failure of a valve to close completely, allowing reversed flow

valvular insufficiency can be caused by many processes, some of which are acute, whereas stenosis is almost always due to chronic abnormality of the valve cusp

Question 2

Contrast the age of presentation for senile calcific aortic stenosis v. stenotic bicuspid valve

Answer 2

senile calcific aortic stenosis 70s-90s

bicuspid aortic valves (greater than normal mechanical stress) 50s-70s

Question 3

Describe how calcific lesions are deposited on the valve.

Answer 3

may be connected to chronic injury due to hyperlipidemia, hypertension, inflammation and other factors

definitely differs from atherosclerosis in the abnormal valve contain cells resembling osteoblasts that synthesize bone matrix proteins and promote the deposition of calcium salts

Question 4

Describe the classic morphology of calcific aortic stenosis.

Answer 4

heaped-up calcified masses within the aortic cusps that ultimately protrude through the outflow surfaces into the sinuses of Valsalva, preventing the opening of the cusps, free edges are not normally involved

calcific process begins at valvular fibrosa (pts of max. cusp flexion, near their attachment); commissural fusion is not usually seen

narrowing from 4 cm2 to .5-1 cm2

Question 5

Describe the microscopic features of a senile calcific stenotic valve.

Answer 5

layered architecture of valve is preserved, functional area is decreased, causing outflow obstruction

Question 6

What are late complications of bicuspid aortic valve?

Answer 6

aortic stenosis or regurgitation
infective endocarditis
aortic dilation and or dissection (structural abnormalities of the aortic wall commonly accompany bicuspid aortic valve, even when the valve is hemodynamically normal)

Question 7

Describe the morphology of a bicuspid aortic valve.

Answer 7

usually the two functional cusps are of unequal size, with the larger cusp having a midline raphe (common site of calcific deposits), resulting in incomplete commissiural separtaion during development, less frequently cusps are equal size with absent raphe

Question 8

What process may lead a bicuspid aortic valve to become incompetent.

Answer 8

as a result of aortic dilation, cusp prolapse of infective endocarditis

Question 9

How could you distinguish bicuspid valve from fusion occurring during rheumatic disease?

Answer 9

in acquired deformity, the fused commissure produces a conjoined cusp that is generally twice the size of nonconjoined cusp, the mitral valve is generally normal in congenital bicuspid aortic valve

Question 10

Contrast rheumatic fever and rheumatic heart disease.

Answer 10

fever: an acute, immune response to group A streptococci M proteins that cross-react with host tissues that occurs a few weeks after an episode of group A strep pharyngitis, CD4 T cells specific for streptococcal peptides also react with self proteins int eh heart and produce cytokines that activate macrophages; acute rheumatic carditis is a frequent manifestation during the active phase of fever and may progress over time to chronic rheumatic heart disease

HD: characterized principally by deforming fibrotic valvular disease particularly mitral stenosis

Question 11

Name and describe the focal inflammatory lesions that are found in the heart during RHD.

Answer 11

aschoff bodies are distinctive lesions of teh heart which consist of foci of lymphocytes (primarily T cells) occasional plasma cells and plump activated macrophages called anitschkow cells (pathognomonic)

Question 12

What is a “caterpillar cell”?

Answer 12

anitschkow cells have a central round to ovoid nuclei in which the chromatin is disposed in a central, slender, wavy ribbon; these bess are nicknamed caterpillar cells

aschoff bodies may be found in any of the three layers of the heart, causing pericarditis, myocarditis or endocarditis

Question 13

Where would you find vegetations in a patient with rheumatic heart disease

Answer 13

verrucae are found along the lines of closure, inflammation of the endocardium and left sided valves typically results in fibrinoid necrosis within the cusps or along the tendinous cords, with the verrucae overlying these areas

Question 14

What are MacCallum plaques?

Answer 14

irregular thickenings indued by subendocaridal lesions, perhaps exacerbated by regurgitant jets, usually in the left atrium

Question 15

What are the cardinal changes in the mitral valve in chronic rheumatic heart disease?

Answer 15

valve leaflet thickening with commissural fusion
shortening (fish mouth or buttonhole stenoses)
thickening and fusion from tendinous cords

Question 16

What is the squaquelae that follows mitral stenosis by rheumatic heart disease?

Answer 16

left atrium progressively dilates and may harbor mural thrombi, in the appendage or along the wall (can embolize)
long standing congestion causing pulmonary vascular and parenchymal changes and in time lead to right ventricular hypertrophy

Question 17

Describe the microscopic view of mitral leaflets in rheumatic heart disease.

Answer 17

acute inflammation eventually leads to diffuse fibrosis and neo-vascularization that obliterate the originally layers and avascular leaflet architecture, Aschoff are rarely seen long after the initial infection

Question 18

What type of immune reaction is Rheumatic Fever?

Answer 18

combination of antibody and T cell mediated reactions

Question 19

What are the clinical manifestations of acute rheumatic fever?

Answer 19

acute carditis: pericardial rub, weak heart sounds, tachy, and arrhthymias
migratory polyarthritis in which one large joint after another becomes painfully swollen for a period of days then subsides spontaneously

Question 20

Briefly characterize infective endocarditis.

Answer 20

colonization or invasion of the heart valves or the mural endocardium by a microbe, leads to the formation of vegetations composed of thrombotic debris and organisms, often associated with the destruction of the underlying cardiac tissues

aorta, aneurysmal sacs, other blood vessels and prosthetic devices can also become infected

Question 21

Contrast acute infective endocarditis and sub-acute infective endocarditis.

Answer 21

acute: usually infection of previously normal heart valve by a highly virulent organism that produces necrotizing, ulcerative destructive lesions (requires surgery, often deadly)
sub-acute infective endocarditis: orgs of lower virulence causing insidious infections of deformed valves that are less destructive , often cured with antibiotics

Question 22

What are common antecedent disorders that can predispose to endocarditis?

Answer 22

rheumatic heart disease, mitral valve prolapse, degenerative calcific valvular stenosis, bicuspid aortic valve, prosthetic valves and unprepared and repaired congenital defects

Question 23

Differentiate the causative organisms of endocarditis based on the patients risk factors

Answer 23

abnormal valves: viridans streptococci
IV drug users: S. aureus
prosthetic valve: coagulase-negative staphylococci

other common bacteria:
enterococci
Haemophilus
Actinobacillus
Cardiobacterium
Eikenella
Kingella
(commensals in the oral cavity)

Question 24

Describe the morphological hallmarks of infective endocarditis.

Answer 24

friable, bulky, potentially destructive vegetations containing fibrin, inflammatory cells and bacteria or other organisms on the heart valves (aortic and mitral valves are the most common sites of infection)

vegetations can erode the underlying myocardium and produce abscess, emboli can be shed from the vegetations (which can develop septic infarcts of mycotic aneurysms)

Question 25

What is the long term course of vegetations of sub-acute infective endocarditis?

Answer 25

often have granulation tissue indicative at healing at their bases, with time fibrosis, calcification and a chronic inflammatory infiltrate can develop

Question 26

What are the clinical features of infective endocarditis?

Answer 26

acute: rapidly developing fever, chills, weakness and lassitude, fever in the elderly may be slight or absent

complications begin within the first few weeks of onset including murmurs or immune complex deposition causing glomerulonephritis

Duke criteria look at things like micro-thromboemboli; erythematous or hemorrhagic non-tender lesions on the palms or soles, subcutaneous nodules in the pulp of digits and retinal hemorrhages

Question 27

What does atherosclerosis have to do with pulmonary hypertension?

Answer 27

it is unusual to find atherosclerosis in the pulmonary veins, or any veins unless they are under high pressure

Question 28

What are the typical associations with the following murmurs:
crescendo-decrescendo murmur
holosystolic murmur
diastolic rumble
wheezes and crackles

Answer 28

crescendo-decrescendo: aortic stenosis
holosystolic murmur: mitral regurgitation
diastolic murmur: aortic stenosis
wheezes and crackles: edematous airways causing airway obstruction

Question 29

What lesion is associated with fish mouth/button hole valve?

Answer 29

bicuspid aortic stenosis

Question 30

Patients with bicuspid aortic valve are at increased risk for dilation of aortic root and aneurysms of the ascending aorta, what is the pathological change often seen in the aortic wall of these patients.

Answer 30

cystic medial degeneration (disorganization of the elastin fibers) which is classically seen in Marfans, HTN and bicuspid valve