Valvular Diseases - Cochran

Question 1

Describe the structure & function of normal cardiac valves.

Answer 1

Lined by endothelium and divided into leaflets. If AV valve, connected to ventricle via chordae tendineae & papillaries.

Function to allow unidirectional flow of blood.

Question 2

What can cause valvular insufficiency?

Answer 2

Functional regurgitation (disruption of supporting structure, eg aortic dilation)

Structural disease affecting the valve cusps.

Question 3

Which are more frequent: Stenoses of insufficiencies?

Answer 3

Stenoses.

Question 4

What is the most common congenital valvular abnormality? What does this predispose to?

Answer 4

Bicuspid aortic valve, which is more prone to calcification.

Question 5

Calcific Aortic Stenosis

Describe the pathophysiology.

Who does it generally affect?

Answer 5

“Wear & Tear” resulting in fibrosis and eventual calcification.

Wear & tear results in fibrosing and eventual calcification of the valves.

Occurs in normal valves in very late life (8th-9th decades), as well as in abnormal valves in the 5th-6th decades.

Question 6

What is the signifiance of a Notch mutation in valvular heart disease?

Answer 6

Notch is involved in signaling during heart valve development; mutation predisposes to heart pathologies including CAS.

Question 7

Calcific Aortic Stenosis

Describe its morphology.

Answer 7

Calcific Aortic Stenosis

Calcified masses in cusps, rarely involving the cuspal edges.

No fusion of commissures.

Question 8

Mitral Annular Calcification

Describe the pathogenesis.

Who does it affect?

What are its complications?

Answer 8

Mitral Annular Calcification

Wear & tear degeneration resulting in calcification on the base of the valve (fibrous ring).

Usually women >60, especially with myxomatous valves or increased LV pressure.

Doesn’t affect function, but forms sites for thrombi/infection.

Question 9

Mitral Degeneration

Describe the pathogenesis.

Who does it affect?

What are its complications?

Answer 9

Mitral Degeneration

Myxoid changes weaken the mitral valve, causing it to prolapse back into the left atrium during systole.

Young women, and those with connective tissue disorders (Marfan, Ehler-Danlos).

Usually asymptomatic. Sometimes IE, regurgitation, formation of thrombi and arrhythmia.

Question 10

What is the auscultatory finding of mitral prolapse, and why does it occur?

Answer 10

Holosystolic “blowing” murmur. During systole, left ventricular contraction causes the valve to prolapase into the Left atrium, creating a “blowout” sound akin to a parachute inflating.

Question 11

What valve is most typically affected chronic rheumatic fever?

What is the trigger for ARF?

Answer 11

Usually mitral valve, but may also involve the aortic.

Preceding group A Strep pharyngitis infection.

Question 12

Acute Rheumatic Fever

Describe the 3 components of its pericarditis.

Answer 12

Acute Rheumatic Fever

“Bread & Butter” pericarditis.

Myocarditis with Aschoff bodies (eosinophilic foci with lymphocytes, plasma cells, & anitschkow cells).

Endocarditis with formation of MacCallum plaques (irregular fibrous thickening), fibrinoid necrosis & verrucae.

Question 13

A patient presents with aortic stenosis. How could you distinguish calcific stenosis from that caused by rheumatic fever based on the heart findings alone?

Answer 13

Aortic stenosis due to rheumatic fever would be accompanied by mitral stenosis.

Involvement of the cusp edges.

Fusion of the commissures.

Question 14

Describe the findings seen in chronic rheumatic heart disease.

Answer 14

Valve leaflet thickening

Commissure fusion (“Fishmouth” or “Buttonhole” deformities)

Thickening of chordae tendineae

Question 15

Rheumatic Heart Disease

Describe the pathogenesis.

Answer 15

Rheumatic Heart Disease

GAS pharyngitis generates antibody response against M protein, which is then directed against an unknown heart antigen. (Type II HSR)

(some genetic predisposition to this molecular mimicry response)

Question 16

Rheumatic Heart Disease

Describe the criteria used to diagnose this disease.

Answer 16

Rheumatic Heart Disease

JONES criteria (major manifestations; Joint pain, heart involvement, Nodules, Erythema marginatum, Sydenham chorea)

Minor criteria: Fever, elevated ESR/ARPs.

Positive ASO or Anti-DNAse B titers.

Question 17

Rheumatic Heart Disease

When does chronic rheumatic disease develop, relative to an acute GAS infection?

What role do recurrent infections play?

Answer 17

Rheumatic Heart Disease

Can take years or decades to develop.

Recurrent infections & relapses increase the risk of developing chronic disease.

Question 18

Infectious Endocarditis

Distinguish between acute and subacute infections.

Answer 18

Infectious Endocarditis

Acute endocarditis involves highly virulent organisms affecting a normal valve. Infection is necrotizing & ulcerative, requiring surgery and resulting in high mortality.

Subacute preferentiallya ffects deformed valves, is less destructive and may be managed by antibiotics alone.

Question 19

Infective Endocarditis

Who is predisposed to IE?

What organisms are generally responsible?

Answer 19

Infective Endocarditis

Those with cardiovascular abnormalities, or with immunosuppression (eg diabetics, alcoholics, cancer patients). IV drug users.

Strep viridans > Staph Aureus* > commensals (eg staph epidermidis)

*SA highest in IVDUs.

Question 20

Infective Endocarditis

What valves are most commonly affected? Why is this different in IVDUs?

Describe the lesion.

Answer 20

Infective Endocarditis

Usually mitral and aortic. IVDUs contract endocarditis from venous inoculation, so tricuspid valve is involved.

May range from mild fibrosis & granulation tissue reaction, to formation of bulky, friable vegetations at the bases of valves. May erode the myocardium.

Question 21

Infective Endocarditis

What should be present on histology?

Answer 21

Infective Endocarditis

Abundant neutrophils, dense regions of bacteria corresponding with the vegetations.

Question 22

Infectious Endocarditis

Describe the criteria used in the diagnosis of this disease.

Answer 22

Infectious Endocarditis

Duke criteria: Major (positive culture, echo findings, & valvular insufficiency), Minor (predisposing lesion or IVDU, fever, & septic emboli)

Question 23

Recall the names given to of septic embolization to the following sites:

Nail bed

Palms & soles

Digits

Retina

Answer 23

Nail bed: Splinter hemorrhages

Palms & soles: Janeway lesions

Digits: Osler nodes

Retina: Roth spots

Question 24

Infectious Endocarditis

What are its complications?

How is it treated?

Answer 24

Infectious Endocarditis

Valvular stenosis/insufficiency, myocardial abscess/perforation, septic emboli, glomerulonephritis.

IV antibiotics and possibly valve replacement.

Question 25

_Nonbacterial Thrombotic Endocarditis_ What are the valve findings? Describe its pathogenesis & etiology.

Answer 25

_Nonbacterial Thrombotic Endocarditis_ Deposition of fibrin, platelets, & other blood products (thromboses!). May result in emboli & infarcts. Small, noninflammatory & nondestructive lesions lining the cusp edges. Results from hypercoagulable states. Associated with mucin producing adenocarcinomas & endocardial trauma.

Question 26

_Libman-Sacks Endocarditis_ What is it associated with? Describe its morphology.

Answer 26

_Libman-Sacks Endocarditis_ Systemic Lupus Erythematosus (Anti-PL antibodies present). Forms intensely inflamed verrucae on valve leaflets & endocardium. Targets mitral, tricuspid valves.

Question 27

_Carcinoid Syndrome_ Describe its etiology & pathogenesis. What impact can this have on the heart?

Answer 27

_Carcinoid Syndrome_ A result of carcinoid tumors in tissues such as lung and GI, which produce vasoactive products resulting in flushing, nausea, vomiting, etc. 50% of carcinoid syndrome results in carcinoid heart disease: "plaque-like fibrosis of right-heart endocardium & valves" probably due to endothelial damage.

Question 28

_Carcinoid Heart Disease_ Why is the right heart preferentially affected? Where do the carcinoid tumors have to be located? When can the left heart be affected?

Answer 28

_Carcinoid Heart Disease_ Many of the vasoactive agents are inactivated by MAO, which is highly concentrated in the lungs. GI with metastasis to liver, or anywhere that dumps to non-portal venous system. In primary lung carcinoids, or tumors that secrete extremely high levels of vasoactive produces.

Question 29

_Carcinoid Heart Disease_ Describe the changes found in the heart.

Answer 29

_Carcinoid Heart Changes_ Thickening of the endocardium. Expansion of smooth muscle cells & collagen. May result in tricuspid insufficiency or pulmonic stenosis.

Question 30

What problems are associated with both mechanical and biological heart prosthesis? What problems are distinct to either?

Answer 30

Both are more prone to infectious endocarditis. Mechanical prosthesis are a possible substrate for thromboembolus formation. Cow & Pig valves are prone to deterioration; half need replacement by 15 years.