Valvular Disease Robbins pg. 388-395

Question 1

Valvular stenosis (failure of a valve to open completely) is almost always due
to what?

Answer 1

a primary cuspal abnormality and is virtually always

a chronic process (e.g., calcification or valve scarring).

Question 2

What is valvular insufficiency?

Answer 2

Insufficiency results from failure of a valve to close completely, thereby allowing regurgitation (backflow) of blood.

Question 3

By far the most common congenital valvular lesion is what?

Answer 3

a bicuspid aortic valve with a frequency of 1% to 2% of all live births

Question 4

What commonly causes bicuspid aortic valves?

Answer 4

mutations including those affecting proteins of the Notch signaling pathway

Question 5

What is degenerative valve disease?

Answer 5

A term used to describe changes that affect the integrity of valvular ECM

Question 6

What are some possible changes associated with degenerative valve disease?

Answer 6

• Calcifications, which can be cuspal (typically in the aortic
  valve) or annular (in the mitral valve)
• Decreased numbers of valve fibroblasts and myofibroblasts
• Alterations in the ECM
• Changes in the production of matrix metlloproteinases or their inhibitors

Question 7

What is the most common cause of

aortic stenosis?

Answer 7

Calcific aortic degeneration (common with age but also can be pathogenic- caused by the usual suspects- hyperlipidemia, inflammation, etc.)

Question 8

If calcification inhibits valvular function, how does the heart respond?

Answer 8

Cardiac output is maintained only by virtue of concentric left ventricular hypertrophy, leading to ischemia and angina and potentially CHF

Question 9

What is myxomatous degeneration of the mitral valve?

Answer 9

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

Question 10

Suspected causes of primary myxomatous valvular degeneration?

Answer 10

an underlying (possibly systemic) intrinsic defect of connective tissue synthesis or remodeling is likely.

Thus, myxomatous degeneration of the mitral valve is a common feature of Marfan syndrome (due to fibrillin-1
mutations), and occasionally occurs in other connective tissue disorders

Question 11

Suspected causes of secondary myxomatous valvular degeneration?

Answer 11

Secondary myxomatous change presumably results from injury to the valve myofibroblasts, imposed by chronically aberrant hemodynamic forces.

Question 12

Describe the clinical symptoms of a Myxomatous Mitral valve

Answer 12

Most patients are asymptomatic, and the valvular abnormality is discovered only incidentally on physical examination.

In a minority of cases, patients may complain of palpitations, dyspnea, or atypical chest pain

Question 13

Patients with primary myxomatous degeneration

also are at increased risk for the development of what?

Answer 13

infective endocarditis, as well as sudden cardiac death du to ventricular arrhythmias

stroke can rarely occur

Question 14

What is rheumatic valvular disease/

RHD?

Answer 14

Acute rheumatic fever is a hypersensitivity reaction classically attributed to antibodies directed against group A streptococcal molecules that also are cross-reactive with host antigens, especially in the heart

Question 15

T or F. RHD is associated with inflammation of all
parts of the heart, but valvular inflammation and scarring produces
the most important clinical features

Answer 15

T.

Question 16

What does the valvular disease associated with RHD take the form of?

Answer 16

deforming fibrotic mitral stenosis- The chronic fibrotic lesions are the predictable consequence of healing and scarring associated with the resolution of the acute inflammation

rheumatic heart disease is essentially the ONLY cause of acquired mitral stenosis

Question 17

When do symptoms of acute rheumatic fever begin?

Answer 17

Symptoms in all age groups typically begin 2 to 3 weeks after streptococcal infection, and are heralded by fever and migratory polyarthritis

Question 18

What is migratory polyarthritis?

Answer 18

One large joint after another becomes painful and swollen

for a period of days, followed by spontaneous resolution with no residual disability

Question 19

The diagnosis of acute rheumatic fever is made based on

serologic evidence of previous streptococcal infection in conjunction with two or more of the so-called Jones criteria

Answer 19

conjunction with two or more of the so-called Jones criteria:
(1) carditis;
(2) migratory polyarthritis of large joints;
(3) subcutaneous nodules;
(4) erythema marginatum skin
rashes; and

(5) Sydenham chorea, a neurologic disorder
characterized by involuntary purposeless, rapid movements
(also called St. Vitus dance)

Question 20

T or F. After an initial attack and the generation of immunologic
memory, patients are increasingly vulnerable to disease reactivation with subsequent streptococcal infections.

Answer 20

T. Carditis is likely to worsen with each recurrence, and

the damage is cumulative.

Question 21

What is infectious endocarditis?

Answer 21

Microbial invasion of heart valves or mural endocardium—often with destruction of the underlying cardiac tissues—characteristically results in bulky, friable vegetations composed of necrotic debris, thrombus, and organisms.

Question 22

Common causes of infectious endocarditis?

Answer 22

Although fungi, rickettsiae (agents of Q fever), and chlamydial species can cause endocarditis, the vast majority of cases are caused by extracellular
bacteria