Pathology

Question 1

What are the 2 major valvular heart disease?

Answer 1

1. Stenosis: obstruction caused by failure of the heart to open completely (inhibiting forward flow)
2. Regurgitation (insufficiency/incompetence): reversed flow caused by failure of valve to close completely

Question 2

What are the 4 pathologic mechanism of stenosis and regurgitation diseases?

Answer 2

1. Rheumatic Heart Disease
2. Degenerative Heart Disease
3. Congenital Heart Disease
4. Infective Endocarditis

Question 3

What is the pathogenesis of Rheumatic Heart Disease?

Answer 3

1. Steptoccocal infection when aged 5-15
2. Acute rheumatic fever
3. Chronis rheumatic heart disease 20-40 years later
4. Valve sequelea (mitral valve ++)

Question 4

What are the 2 main causes of degenerative Heart Disease?

Answer 4

1. Degenerative (Senile) Calcific Aortic Stenosis (AS) (most common in > 65 y/o). This causes calcified masses, stenosis but NO commissural fusion.
2. Bicuspid Aortic Valvular Stenosis. This results in fibrosis, superimposed calcification and incompletely separated cusp (fusion). It develops earlier than degenerative AS.

Question 5

What are the 2 main pathological manifestations of Congenital Heart Disease?

Answer 5

• Mitral Valve Prolapse (common cause of mitral regurgitation). It is autosomal dominant and is caused by an accumulation of glycosaminoglycan material associated with loss of collagen and elastic tissue. Complications include ruptured chordae.
• Bicuspid Aortic valve

Question 6

What is the most fatal valvular injury/pathology?

Answer 6

Infective Endocarditis

Question 7

What are the 2 types of Infective Endocarditis?

Answer 7

• Nonbacterial thrombotic endocarditis (NBTE): causes vegetation. 50% occur in patients who are in hypercoagulable state or disseminated intravascular coagulation (trauma, AIDS, adenocarcinoma). Can cause hemorrhagic cerebral infarct (systemic effect).
• Infective endocarditis (IE): causes vegetation and stenosis. Often fatal. They manifest in acute bacterial endocarditis (very sick patients) or subacute bacterial endocarditis (insidious clinical course). Right sided valve IE can be caused by intravenous drug use, fungi and can emboli to lungs.

Question 8

What is the pathogenesis of infective endocarditis?

Answer 8

1. Endocardial surface injury (turbulent or foreign body)
2. Platelet-fibrin-thrombus formation at site of injury
3. Bacterial entry to circulation
4. Bacterial adherence to injured endocardial surface.

Question 9

What is the main complication of infectious valvular disease ?

Answer 9

• Embolisms
• Immune complex deposits to other organs

Question 10

What is the main compensation mechanism that the heart uses in response to chronic valvular disease?

Answer 10

Concentric and eccentric hypertrophy of the ventricle.