Aortic Stenosis

“Senile” calcific aortic stenosis.

Degeneration and calcification of bicuspid aortic valve.

Chronic Rheumatic Disease

Endocardium

Fibrosa

Spongiosa Elastic fibers in black

Aortic valve structure Ventricular side

1 Calcification

2 3 due to aortic dissection • Hypertension • disorders Marfan’s: 1 in 5000. 70-85% familial (Autosomal dominant) Fibrillin-1 (15q21) ~ 500 distinct mutations

4 Medial degeneration without atherosclerosis

Mitral Stenosis

• Chronic Rheumatic Heart Disease

• (Rare) Mitral annular calcification Myxoma

5 Acute Immunologically mediated, following 1-6 weeks after pharyngitis with Group A Streptococcus in 3% of those infected. ?Antibodies ? Hypersensitivity reaction induced by streptococcal M proteins with cross-reaction with similar antigenic determinants in joints, heart, skin, CNS.

Clinical Diagnosis: revised Jones criteria

Acute Rheumatic Fever

Pancarditis Pericarditis Myocarditis (Aschoff body) with sterile vegetations

Death in acute rheumatic fever is very rare (<1%) and due to cardiac involvement

6 Aschoff body of acute rheumatic : a cardiac

Acute rheumatic fever: involvement of mitral chordae tendineae

7 Native chordae bound together by fibrous tissue in chronic rheumatic mitral valve disease

Chronic Rheumatic Heart Disease Follows Acute Rheumatic Heart Disease by decades. MV involved in 65-70% MV & AV in 25% Mitral stenosis, aortic stenosis. Arrhythmias (A. fib. with left atrial enlargement). Heart failure. Predisposed to infective endocarditis.

8 9 Chronic Rheumatic Heart Disease: “Fishmouth” deformity of the mitral valve

Mitral Valve Prolapse • 2 populations: women in 20s; men in 40-50s; the gross and microscopic appearances of the valves are the same. • Most are asymptomatic • Mid-systolic click • Rarely: , dyspnea, fatigue, or psychiatric manifestations • ~3% have complications: Infective endocarditis Mitral insufficiency Thrombus formation with embolization Arrhythmia/sudden death (unknown mechanism)

10 Normal (aortic) valve structure

Myxomatous, prolapsing mitral valve

11 “Myxomatous” mitral valve

12 Acute endocarditis of mitral valve

13 Rupture of MV papillary muscle with inferior wall MI

The following 6 slides on valve prostheses were not presented in the lecture on 1-4-06

14 Heart Valve Prostheses: Complications • Mechanical: component failure • Bioprostheses: degeneration with calcification • Both: Paravalvular leak, endocarditis. Thrombosis and tissue overgrowth are less common in bioprostheses than in mechanical valves.

Bioprosthetic (Hancock)valve: Degeneration and tissue overgrowth

15 Thrombus occluding AV prosthesis

16 Thrombus covering mitral valve prosthesis (viewed from opened left atrium

Endocarditis (arrows on vegetations) of ball valve prosthesis (Starr-Edwards)

17