Valvular Heart Disease

Question 1

stenosis

Answer 1

failure of a valve to open completely, obstructing forward blood flow.
- results from severe fibrosis or calcification and distortion of the valvular leaflet anatomy - slow to develop

Question 2

insufficiency

Answer 2

failure of a valve to close completely thereby allowing reverse flow of blood. either intrinsic disease of the valve cusps or damage to associated structures and by slow or rapid

Question 3

pure disease

Answer 3

if only stenosis or insufficient is present

if both -> mixed lesion

Question 4

consequences of valvular lesions

Answer 4

varies for slight and physiologically unimportant to severe requiring surgical intervention
- depends on the rate of development of the lesion

Question 5

secondary changes

Answer 5

lungs and liver are most affected - congestion of pulmonary htn

Question 6

etiology : mitral stenosis

Answer 6

post inflammatory scarring ( rheumatic heart disease )

Question 7

etiology : aortic stenosis

Answer 7

calcification of anatomically normal and congentially bicuspid aortic valve ( degenerative calcific AS)

• senile calcific aortic stenosis*
• post inflammatory scarring ( rheumatic heart disease)

Question 8

etiology of aortic regurg

Answer 8

-aortic dilation *
 intrinsic valvular disease -> rheumatic 
- infective endocarditis 
-syphilitic aortitis 
-ankylosing spondylitis 
-rheumatic arthritis 
-marfan syndrome

Question 9

etiology : mitral regurg

Answer 9

abnormal leaflets and commissures

• mitral valve prolapse * (myxomatous degeneration)
• post inflammatory scarring
• infective endocarditis
• fen-phen-induced valvular fibrosis

abnormal tensor apparatus

• rupture papillary muscle
• papillary muscle dysfunction
• rupture of chordae tendineae

abnormal left ventricular cavity or annulus

• LV enlargement ( myocarditis , dilated cardiomyopathy)
• calcification of mitral ring

Question 10

critical stenosis

Answer 10

2/3 reduction of valve area or a pressure gradient of at least 50 mm HG

Question 11

pathology of mitral valve prolapse

Answer 11

• too much valve tissue with billowing up of tissues between chordal attachments
• leaflets are thickened , soft grey white gelatinous appearing and have atrial smooth muscle
• chordae are elongated and attenuated or thinned
• soo much spongiosa -> floppy valve

Question 12

mitral valve etiology

Answer 12

unknown: underlying connective tissue problem

Question 13

mitral annular calcification

Answer 13

see stony hard calcified nodules behind the leaflets

• nodules give site for thrombin to form-> embolized -> stroke
• infective endocarditis
• women over 60 and ladies with a myxomatous mitral valve or elevated left ventricular pressure

Question 14

clinical features: rheumatic heart disease

Answer 14

major criteria:

• carditis
• migratory polyarthritis
• chorea
• subcutaneous nodules
• erythema marginatum

minor criteria:

• arthralgia
• fever
• elevated acute phase reactants
• EKG changes ( increased P-R interval)

evidence of prior streptococcal infection

• • throat culture or rapid strep Ag test
• elevated or rising strep antibody titer

2 majors or one major and 2 minor and ecidnce of prior strep infection

Question 15

epidemiology of RHD

Answer 15

1-3% of strep infection lead to RF

Question 16

Pathogenesis of RF

Answer 16

• heightened immunologic reactivity to step Ags with resultant ABs and possible cytotoxic T cells that cross-react with cardiac antigens. this group A carbohydrate moiety shares antigenic similarity with a glycoprotein found in cardiac calces the M antigen may cross react with myocardial Antigens.
• possible toxic effect of a toxin secreted by strep ( anti streptolysin O)
• possible genetic predisposition

Question 17

pathology of RF

Answer 17

pancarditis may occur ( endocardial to pericardial inflammation)

1. endocarditis - valvulitis with verrucae ( small vegetations along line of closure of mitral valve leaflet)
2. myocarditis - aschoff bodies -> pathognomonic
   - inflammatory focus of lymphocytes, plasma cells and plump modified histiocytes (anitschkow macrophages) surround an area of central fibrinoid necrosis
3. pericarditis - a bread and butter -( mozzarella) fibrinous pericarditis is present - friction rub

Question 18

chronic rheumatic heart disease

Answer 18

65-70% mitral
mitral and aortic - 25%
- diffuse fibrosis , commissural fusion, calcification, post-inflamm neovascularization
-mitral valve thickening, shortening and fusion of the chordae tendinae -> fish mouth
-COMMISSURAL FUSION
- complications: stenosis or insufficiency and increased incidence of infective endocarditis

Question 19

carcinoid heart disease

Answer 19

cardiac manifestation of the systemic syndrome cause by carcinoid tumors

• tumor made of neuroendocrine cells and secretes vasoactive amines
• amine are broken down in liver and lung- > if they arent broken down-> you get carcinoid syndrome
• results in a thickening of heart valve - > amines form plaques that thickens the endocardium - made of smooth muscle cells within a matrix
• limited to the heart because they get deactivated in the lung

Question 20

valve replacement

Answer 20

60% of substitute valve recipients get a serious prosthesis related problem within 10 yrs post-op

Question 21

mechanical heart valves

Answer 21

• made of something other than tissue ( metal, plastic)
• prone to thromboembolic complications - local obstruction by thrombus, patient requires long term anticoagulation
• lasts a long time but the anti-coag is a problem if people fall or want to be in contact sports

Question 22

tissue valves

Answer 22

bioprostheses consisting of chemically treated animal tissue mounted on a prosthetic frame

• tissue valves are flexible and function somewhat like natural semilunar valves
• structural deterioration is a major failure mode of bioprostheses, with calcification and/or tearing causing secondary regurgitation
• will probably need a replacement in 10-20 yrs

Question 23

complications of valve replacement

Answer 23

• infective endocarditis
• hemolysis
• inadequate or exuberant healing - paravalvular leak or overgrowth of fibrous tissue