5. Clinical consequences
1. Stenosis – failure of a valve to open completely,
obstructing forward flow.
2. Insufficiency (regurgitation ) - failure of a valve to
close completely, allowing (backflow) of blood.
Stenosis or regurgitation can occur alone or together in
the same valve.
7. Clinical consequences
• Abnormal flow through diseased valves - produces
abnormal heart sounds (murmurs)
• severe lesions can even be palpated as thrills.
• severity - quality and timing of the murmur
(e.g., harsh systolic or soft diastolic murmurs)
9. Congenital valvular heart diseases
most common – bicuspid aortic valve
• neither stenotic nor incompetent through early life
• more prone to early and progressive degenerative
calcification
11. Most Common Causes
1. AS: calcification of anatomically normal and
congenitally bicuspid aortic valves
2. AR: dilation of ascending aorta, usually related to
hypertension and aging
3. MS: rheumatic heart disease
4. MR: myxomatous degeneration (mitral valve prolapse)
12. Aortic stenosis
Most common cause –
calcification of
1.
anatomically normal (senile calcific aortic stenosis) and
2.
congenitally bicuspid aortic valves
13. Pathogenesis
• Degenerative changes due to aging process (wear and tear)
• Repetitive mechanical stresses to valves —40 million
beats/yr
• chronic injury due to hyperlipidemia, hypertension,
inflammation, atherosclerosis leads to .......
• dystrophic calcification (deposits of calcium phosphate salts)
• Normal valves - Senile calcific aortic stenosis >70 yrs
• Bicuspid valves – more stress – earlier calcification <50 yrs
15. Clinical Features
• gradual narrowing of the valve orifice ( 0.5 to 1 cm2 in severe
AS ; normal, ∼4 cm2 )
• Left ventricular pressures - > 200 mm Hg
• Pressure overload concentric LVH
• hypertrophied myocardium -prone to ischemia and angina
• Systolic and diastolic dysfunction – CHF
16. calcific aortic stenosis
Prognosis
• Asymptomative at earlier stage – excellent
• Late stage - development of angina, CHF, or syncope
poor prognosis
• without surgical intervention, 50% to 80% die within 2
to 3 years
17. Most Common Causes
1. AS: calcification of anatomically normal and
congenitally bicuspid aortic valves
2. AR: dilation of ascending aorta, usually related to
hypertension and aging
3. MS: rheumatic heart disease
4. MR: myxomatous degeneration (mitral valve prolapse)
18. Myxomatous Mitral Valve
• Mitral prolapse - parachute-like protrusion of value into the
left atrium
• “floppy” and prolapse— balloon back into LA during systole.
• Men = women
Two types
1. P
2. Secondary where MR due to others(e.g., IHD).
19. Myxomatous Mitral Valve
Causes
1. primary myxomatous degeneration
• intrinsic defect of connective tissue synthesis or remodeling
(e.g., Marfan syndrome)
2. Secondary
• results from injury to the valve myofibroblasts, by
chronically aberrant hemodynamic forces
20. Pathogenesis
Myxoid degeneration due to accumulation
of glycosaminoglycan, within the connective tissue
matrix of the valve.
many cases, degeneration limited to mitral valve
Marfan syndrome - degeneration is more extensive
and involves other heart valves.
21. Morphology
• Characterized by ballooning
(hooding) of the mitral
leaflets
• affected leaflets are
enlarged, thick, and rubbery
• L A - dilated due to longstanding volume overload.
22. Clinical features
• Most – asymptomatic
• minority - palpitations, dyspnea, or atypical chest
pain
• Auscultation - midsystolic click, caused by abrupt
tension on valve leaflets as valve attempts to close
• diagnosis can be confirmed by echocardiography
23. complications
• 3% - develop complications
(1) IE
(2) MR , sometimes with chordal rupture
(3) stroke or systemic infarct, resulting from embolism
(4) arrhythmias, both ventricular and atrial
25. Most Common Causes
1. AS: calcification of anatomically normal and
congenitally bicuspid aortic valves
2. AR: dilation of ascending aorta, usually related to
hypertension and aging
3. MS: rheumatic heart disease
4. MR: myxomatous degeneration (mitral valve prolapse)
27. Acute Rheumatic Fever
• acute, immunologically mediated, multisystem
inflammatory disease 2- to 3-weeks after group A βhemolytic streptococcal infections (pharyngitis)
• Occurs commonly in children (4 to 9 years)
28. PATHOGENESIS
• Heart valves - common antigenic sequences with GAS
bacteria (Mprotein= Glycoprotein antigen)
• GAS pharygitis - Formation of antistreptococcal Abs
• cross reacts with Cardiac myosin and Sarcolemma
• joints (Antibody against Streptococcal hyaluronic acid
cross reacts with connective tissue proteoglycans)
• Only 3% of infected patients develop rheumatic fever
depends on individual immune response
35. Morphology
Pancrditis
• Pericardium: “Bread and Butter” Pericarditis
• Myocardium: Myocarditis (Scattered Aschoff bodies)
• Endocardium: Fibrinoid necrosis along the lines of
closure of valves forming 1 to 2 mm vegetations
(verrucae)
40. Clinical Features of ARF
• Following upper airway infection with GAS
• Silent period of 2 - 3 weeks
• Sudden onset of fever, pallor, malaise, fatigue
Arthritis - occurs in 75%
41. • two of five major criteria, OR
• one major criterion and two minor criteria
42. Sydenham's chorea
• movement disorder
• described as 'rapid, irregular, aimless and involuntary'.
• affect the muscles in the limbs, face and trunk.
• girls > boys
• 25% - develop chronic rheumatic valve disease.
43. Erythema marginatum
• occurs in < 5% of patients.
• start as red macules that
fade in the centre
• remain red at the edges
• mainly on trunk and
proximal extremities
• but not the face.
46. Chronic rheumatic heart disease
• Develope in 50% of rheumatic carditis.
• 2/3 - women.
• history of rheumatic fever or chorea in 50%
• > 90% - mitral valve is affected
• 25% - Isolated mitral stenosis
• 40% - mixed mitral stenosis and regurgitation
• others - aortic valve , tricuspid and pulmonary valve
47. Pathogenesis
• main pathological process - progressive fibrosis.
• characterized by organization of the acute
inflammation and subsequent scarring.
• Aschoff bodies are replaced by fibrous scar
• Fusion of the mitral valve commissures and shortening
of the chordae tendineae mitral stenosis
