Chapter 11: Valvular Heart Disease

Question 1

Valvular disease MAY result in: a. stenosis b. insufficiency c. both d. neither

Answer 1

c. both

Question 2

What is stenosis?

Answer 2

Stenosis is the failure of a valve to open completely, obstructing forward flow

Question 3

What is the cause of a valvular stenosis?

Answer 3

primary cuspal abnormality stemming from a chronic process (e.g., calcification or valve scarring)

Question 4

What can be forms of insufficiency (in valvular disease)

Answer 4

regurgitation or incompetence

Question 5

What does insufficiency result from?

Answer 5

Failure of a valve to close completely, thereby allowing regurgitation (backflow) of blood

Question 6

What can be a cause of valvular insufficiency?

Answer 6

Valvular insufficiency can result from either intrinsic disease of the valve cusps (e.g., endocarditis) or disruption of the supporting structures (e.g., the aorta, mitral annulus, tendinous cords, papillary muscles, or ventricular free wall) without primary cuspal injury

Question 7

True/false: valvular insufficiency appears abruptly

Answer 7

yes, but can also appear insidiously as a consequence of leaflet scarring and retraction

Question 8

True/false: A valve has either stenosis or regurgitation

Answer 8

Can be, but they may also occur together (in the same valve)

Question 9

Which valve is the most common target? And where is it located?

Answer 9

Mitral valve/bicuspid valve, between the left atrium and the left ventricle

Question 10

How does turbulent flow through a diseased valve typically sound like?

Answer 10

murmurs

Question 11

How do severe lesions that can be externally palpated sounds like?

Answer 11

Thrills

Question 12

The outcome of valvular disease depends on the valve involved, the degree of impairment, the tempo of its development, and the effectiveness of compensatory mechanisms. Name two exapmles. (just for illustration)

Answer 12

For example, rapid destruction of an aortic valve cusp by infection can cause massive regurgitation and the abrupt onset of cardiac failure. By contrast, rheumatic mitral stenosis usually progresses over years, and its clinical effects are well tolerated until late in the course.

Question 13

True/false: Valvular abnormalities can be congenital or acquired (aangeboren/verworven)

Answer 13

True

Question 14

What is the most common congenital valvular lesion?

Answer 14

Bicuspic aortic valve (instead of tricuspid)

Question 15

Name some examples of acquired valve disease?

Answer 15

you obv don’t have to learn these, just for your understanding/illustration

Question 16

What is degenerative valve disease?

Answer 16

Degenerative valve disease is a term used to describe changes that affect the integrity of valvular ECM

Question 17

What are degenerative changes in the heart valve?

Answer 17

• Calcifications • Alterations in the ECM • Changes in the production of matrix metalloproteinases or their inhibitors • Degenerative changes in the cardiac valves

Question 18

What is the most common cause of aortic stenosis?

Answer 18

Calcific aortic degeneration

Question 19

What is myxomatous degeneration of the mitral valve?

Answer 19

one or both mitral leaflets are “floppy” and prolapse—they balloon back into the left atrium during systole

Question 20

Of what syndrome is myxomatous mitral valve typical?

Answer 20

Marfan syndrome (due to mutation)

Question 21

Rheumatic heart disease is the cardiac manifestation of rheumatic fever. What are the most important clinical features?

Answer 21

It is associated with inflammation of all parts of the heart, but valvular inflammation and scarring produce the most important clinical features.

Question 22

How does the rheumatic valvular disease take form?

Answer 22

The valvular disease principally takes the form of deforming fibrotic mitral stenosis; indeed rheumatic heart disease is essentially the only cause of acquired mitral stenosis

Question 23

Has the incidence of rheumatic fever/heart disease increased or decreased in the western world.

Answer 23

Decreased

Question 24

What happens (pathologically) in acute rheumatic fever?

Answer 24

Acute rheumatic fever is a hypersensitivity reaction classically attributed to antibodies directed against group A streptococcal molecules that cross-react with host myocardial antigens

Question 25

The diagnosis of acute rheumatic fever is made based on serologic evidence of previous streptococcal infection in conjunction with two or more of the Jones criteria. What are they?

Answer 25

(1) carditis; (2) migratory polyarthritis of large joints; (3) subcutaneous nodules; (4) erythematous annular rash (erythema marginatum) in the skin; and (5) Sydenham chorea, a neurologic disorder characterized by involuntary purposeless, rapid movements. Minor criteria such as fever, arthralgias, EKG changes, or elevated acute phase reactants also can help support the diagnosis. (i don’t think you should know this but there is like 2 pages on rheumatic fever in the book)

Question 26

What is infective endocarditis (IE)?

Answer 26

Infective endocarditis (IE) is a microbial infection of the heart valves or the mural endocardium that leads to the formation of vegetations composed of thrombotic debris and organisms, often associated with destruction of the underlying cardiac tissues

Question 27

IE can occur acute or subacute. Explain the difference. (this was not discussed in the lecture, don’t think you have to know this)

Answer 27

• Acute endocarditis refers to tumultuous, destructive infections, frequently involving a highly virulent organism attacking a previously normal valve. It is associated with of substantial morbidity and mortality, even with appropriate antibiotic therapy and/or surgery. • Subacute endocarditis refers to infections by organisms of low virulence affecting a previously abnormal heart, especially scarred or deformed valves. The disease typically appears insidiously and—even if untreated— follows a protracted course of weeks to months; most patients recover after appropriate antibiotic therapy.

Question 28

How does an infective endocarditis occur?

Answer 28

Infective endocarditis can develop on previously normal valves, but cardiac abnormalities predispose to such infections; rheumatic heart disease, mitral valve prolapse, bicuspid aortic valves, and calcific valvular stenosis are all common substrates. Prosthetic heart valves, host factors such as neutropenia, immunodeficiency, malignancy, diabetes mellitus, and alcohol or intravenous drug abuse also increase the risk for IE and adversely affect outcomes. (please don’t learn by heart)

Question 29

What causative organisms can occur under which circumstances? (i really don’t think you have to learn this, just skim)

Answer 29

50% to 60% of cases occurring on damaged or deformed valves are caused by Streptococcus viridans, a relatively banal group of normal oral flora. By contrast, the more virulent S. aureus (common to skin) can attack healthy as well as deformed valves and is responsible for 10% to 20% of cases overall; it also is the major offender in infections occurring in intravenous drug abusers. Additional bacterial agents include enterococci and the so-called “HACEK group” (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella), all commensal in the oral cavity. More rarely, gram-negative bacilli and fungi are involved. In about 10% of all cases of endocarditis, no organism is isolated from the blood (“culture-negative” endocarditis) because of previous antibiotic therapy, dif- ficulty in isolating the offending agent, or because deeply embedded organisms within the enlarging vegetation are not readily released into the blood. Foremost among the factors predisposing to endocarditis is seeding of the blood with microbes

Question 30

What are the signs of IE?

Answer 30

Fever! However, in subacute disease (particularly in older adults), fever may be absent, and the only manifestations may be nonspecific fatigue, weight loss, and a flulike syndrome; splenomegaly also is common in subacute cases. By contrast, acute endocarditis often manifests with rapidly developing fever, chills, weakness, and lassitude. Murmurs are present in 90% of patients with left-sided lesions.

Question 31

Major forms of vegetative endocarditis are seen in this picture. What do the ebbriviations stand for + can you explain briefly?

(LSE was not discussed in the lecture)

Answer 31

• The acute rheumatic fever phase of rheumatic heart disease (RHD) is marked by the appearance of small, warty, inflammatory vegetations along the lines of valve closure; as the inflammation resolves, substantial scarring can result.
• Infective endocarditis (IE) is characterized by large, irregular, often destructive masses that can extend from valve leaflets onto adjacent structures (e.g., chordae or myocardium).
• Non-bacterial thrombotic endocarditis (NBTE) typically manifests with small- to medium-sized, bland, nondestructive vegetations at the line of valve closure.
• Libman-Sacks endocarditis (LSE) is characterized by small- to medium-sized inflammatory vegetations that can be attached on either side of the valve leaflets; these heal with scarring.

Question 32

How is nonbacterial thrombotic endocarditis (NBTE) characterized?

Answer 32

Nonbacterial thrombotic endocarditis (NBTE) is characterized by the deposition of sterile thrombi on cardiac valves, typically in those with an underlying hypercoagulable state

Question 33

Can nonbacterial thrombotic endocarditis (NBTE) occur in healthy patients?

Answer 33

Although NBTE can occur in otherwise healthy individuals, a wide variety of diseases associated with general debility or wasting are associated with an increased risk for NBTE—hence the alternate term marantic endocarditis

Question 34

What is the major difference between infective and non-infective endocarditis (on the valve)?

Answer 34

the sterile valvular lesions of NBTE are nondestructive, the infective valvular lesions are destructive

Question 35

True/false: The vegetations in NBTE are typically large (1-5cm in diameter)

Answer 35

False, the vegetations in NBTE are typically small (1 to 5 mm in diameter)

Question 36

True/false: valvular damage is a prerequisite of NBTE

Answer 36

False!

Question 37

What is the precursor of NBTE?

Answer 37

Most common: hypercoagulable states, such as chronic disseminated intravascular coagulation, hyperestrogenic states, and those associated with underlying malignancy, particularly mucinous adenocarcinomas

Question 38

What is an important complication of NBTE?

Answer 38

Embolization