L14-15 Valve Pathology

Question 1

Define incompetent valve

Answer 1

Insufficiency results from failure of valve to close completely allowing regurgitation of blood

Question 2

Define stenotic valve

Answer 2

is failure of a valve to open completely obstructing forward flow

Question 3

What causes murmers

Answer 3

Turbulent flow through diseased valves typically produces murmurs

Question 4

Describe bicuspid aortic valve

Answer 4

▪️1% of population has a congenital bicuspid valve

▪️aortic valve is replaced by complete fibrous tissue or unicommisural

Question 5

What is aortic valve stenosis

Answer 5

Blood is unable to flow freely from left ventricle to the aorta during aortic stenosis

Question 6

Describe aortic valve incompetence

Answer 6

intrinsic abnormality (like endocarditis) or dilation of aortic root due to accumulation of mucus in wall of aorta

Question 7

Where can dilation of atrial root be seen

Answer 7

Idiopathic

Marfan’s syndrome

Question 8

Describe mitral valve incompetence

Answer 8

▪️Floppy mitral valve where the cusps are larger than normal,dome shaped and the chordae tendinae are elongated

Question 9

Define rheumatic valvular disease

Answer 9

Acute, immunologically mediated inflammatory disease that occurs after group A b-hemolytic streptococcal throat or skin infections

Question 10

Clinical features of rheumatic valvular disease

Answer 10

Pan carditis

Valvular inflammation and scarring

Question 11

What does valvular disease principally take the form of

Answer 11

Fibrotic mitral stenosis

Question 12

Pathogenesis of acute rheumatic fever

Answer 12

▪️Hypersensitivity reaction
▪️Antibodies against group A streptococcal molecules that cross react with host myocardial antigens
▪️ab against m proteins of certain streptococcal strains bind to proteins in the myocardium and cardiac valves and cause injury through the activation of complement and Fc receptor-bearing cells

Question 13

What is acute rheumatic fever characterized by

Answer 13

Discrete inflammatory foci called Aschoff bodies

Question 14

What do the Aschoff bodies contain

Answer 14

Collections of lymphocytes (mostly t cells)
Scattered plasma cells
Plump activated macrophages called anitschkow cells associated with zones of fibrinoid necrosis

Question 15

How is the pericardium affected

Answer 15

Fibrinous exudate which can be resolved on its own

Question 16

How is the myocardium involved in rheumatic fever

Answer 16

Myocarditis

Scattered aschoff bodies within interstitial CT

Question 17

Valve involvement in rheumatic fever

Answer 17

Results in fibrinoid necrosis and fibrin deposition along lines of closure forming vegetations

Question 18

What is rheumatic chronic heart disease characterized by

Answer 18

Organization of acute inflammation and subsequent scarring
Aschoff bodies or replaced by fibrous scar so that these regions are rarely seen
Valve cusps and leaflets become permanently thickened and retracted

Question 19

What happens to the mitral valve in chronic rheumatic heart disease

Answer 19

Exhibits leaflet thickening commissural fusion and shortening and thickening and fusion of chordae tendinae
Fibrous bridging across the valvular commissures and calcification create fish-mouth stenosis

Question 20

Most important functional consequence of rheumatic heart disease

Answer 20

Valvular stenosis and regurgitation

Question 21

What happens in tight mitral stenosis

Answer 21

Left atrium progressively dilates causing pressure overload ,precipitating atrial fibrillations formation of large mural thrombi

Question 22

Clinical features of chronic rheumatic heart disease

Answer 22

▪️Acute rheumatic fever in children manifestation is carditis
▪️Symptoms begin 2 to 3 weeks after streptococcal infection
▪️Symptoms are fever and migratory polyarthritis


Question 23

What are usually elevated in acute rheumatic fever

Answer 23

Cultures are negative for streptococci but serum titers of antibodies against one or more streptococcal antigens are elevated

Question 24

What are the Jones criteria

Answer 24

Carditis 
migratory polyarthritis of large joints 
subcutaneous nodules 
erythematous annular rash
Sydenham chorea

Question 25

What is Sydenham chorea

Answer 25

Neurologic disorder characterized by involuntary purposeless rapid movements

Question 26

What are the minor criteria

Answer 26

Fever
arthralgias
EKG changes
elevated acute phase reactants

Question 27

What is ineffective endocarditis

Answer 27

Inflammatory condition affecting the endocardium particularly on the heart valves

Question 28

What does ineffective endocarditis lead to

Answer 28

Leads to the development of large Friable vegetation on the heart valves fragments of these Thrombi split from the main mass and embolize around the breadstream and may impact in distant vessels causing infraction and spread of infection

Question 29

Clinical manifestation of ineffective endocarditis

Answer 29

▪️Patient is feverish and becomes rapidly
▪️the classic organism is Staphylococcus aureus
▪️Usually in intravenous drug abusers because they inject dirty drug solutions affecting the right sided valves

Question 30

What is subacute infective endocarditis

Answer 30

Slow disease that occurs on top of disease valves by rheumatic heart disease or prosthetic
The organism is streptococcus viridian
Vegetations are smaller firmer and embolization is less common 

Question 31

What is the morphology of infective endocarditis

Answer 31

▪️Vegetations are usually 0.5 to 1 cm in subacute and 1 to 2 in acute
▪️Vegetation may be a single or form a merging valve destroying Mass
▪️In acute IE perforation of valve cusp maybe seen or infiltration of the myocardium with abscess formation
▪️Vegetations are on the upper aspect of tricuspid and mitral valves and on the ventricular surface of pulmonary and aortic valves

Question 32

What are the consequences of ineffective endocarditis

Answer 32

▪️Embolus formation: may travel along coronary artery or systemic circulation after impaction,infection weakens the wall of the vessel leading to a weak dilated artery
▪️Valve perforation and destruction leading to spread of infection into the myocardium which may lead to heart failure
▪️ immune complex tissue injury which may cause glomerulonephritis in kidney, vasculitis of skin or Arthralgia in joints