Rheumatic heart disease

VALVULAR HEART DISEASES

8/1/2014

Normal heart valves

Normal heart valves

Valvular heart disease

• A major group of cardiac pathology affecting cardiac valves.

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.

What is STENOSIS ? What is REGURGITATION?

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)

Valvular heart disease

Types

1. Congenital valvular heart diseases

2. Acquired valvular heart diseases

Congenital valvular heart diseases

most common – bicuspid aortic valve

• neither stenotic nor incompetent through early life

• more prone to early and progressive degenerative

calcification

Acquired valvular heart diseases

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)

Aortic stenosis

Most common cause –

calcification of

1. anatomically normal (senile calcific aortic stenosis) and

2. congenitally bicuspid aortic valves

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

MORPHOLOGY

• heaped-up calcified masses on outflow side of cusps

Clinical Features

• gradual narrowing of the valve orifice ( 0.5 to 1 cm2 in

severe AS ; normal, 4 cm∼ 2 )

• Left ventricular pressures - > 200 mm Hg

• Pressure overload concentric LVH

• hypertrophied myocardium -prone to ischemia and angina

• Systolic and diastolic dysfunction – CHF

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

Most Common Causes







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).

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

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.

• Characterized by ballooning

(hooding) of the mitral

leaflets

• affected leaflets are

enlarged, thick, and rubbery

• L A - dilated due to long-

standing volume overload.

Morphology

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

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

Complications

• pronounced hooding

of mitral leaflet with

thrombotic plaques

Most Common Causes







Rheumatic heart disease

1. cardiac manifestation of rheumatic fever.

2. Chronic rheumatic heart disease

Acute Rheumatic Fever

• acute, immunologically mediated, multisystem

inflammatory disease 2- to 3-weeks after group A β-

hemolytic streptococcal infections (pharyngitis)

• Occurs commonly in children (4 to 9 years)

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

Rheumatic Valvular Disease


• Pathological Changes Of Heart In Acute Rhumatic Fever

Morphology

Aschoff bodies or Rheumatic granuloma

• fibrinoid necrosis surrounded by lymphocytes,

plasma cells and plump activated macrophages

(Anitschkow cells)

• pathognomonic of rheumatic carditis

Anitschkow cells

• modified

macrophages

• nuclei that have

central caterpillar-

shaped wavy

chromatin

Aschoff bodies or Rheumatic granuloma

Morphology

Pancarditis:

• Diffuse inflammation and Aschoff Bodies in any of the

3 layers of heart – pericardium, myocardium,

endocardium (including valves)

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)

“Bread and Butter” Pericarditis

Macculum plaques

• irregular thickenings of

endocardium in left

atrium caused by

regurgitant blood flow

Subendocardial fibrosis

Macculum plaques

Vegetations

• vegetations (verrucae)

along the lines of

closure of valves

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%

• two of five major criteria, OR

• one major criterion and two minor criteria

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.

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.

Investigations


1. cardiac manifestation of rheumatic fever.

2. Chronic rheumatic heart disease

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

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

Morphology

• Fibrous bridging across the valves and calcification create

“fishmouth” or “buttonhole” stenoses

Major causes of death in RHD

Cardiac failure

• Bacterial Endocarditis

• Embolism

So…………

The first step in preventing Rheumatic fever &

Rheumatic heart disease is to detect & treat

STREPTOCOCCAL PHARYNGITIS.

Diagnosing a streptococcal pharyngitis

you must know why ………………

Education

Rheumatic heart disease