28. Mitral Valve Disease

Question 1

components of the mitral valve?

Answer 1

mitral leaflets, chordae tendinae, papillary muscles

Question 2

which is more complicated, mitral or semilunar valves?

Answer 2

mitral

Question 3

the papillary muscles contract when?

Answer 3

during systole

Question 4

what is the most common disease affecting mitral valve leaflet tissue?

Answer 4

myxomatous degeneration: loose tissue, results in redundancy

Question 5

what is the result of myxomatous degen?

Answer 5

progressive mitral regurg

Question 6

how does ischemic heart disease affect the mitral valve?

Answer 6

if there is ischemia/infarct of the LV or papillary muscles, the mitral will malfunction and leak

Question 7

2 other diseases that can yield a leaky mitral?

Answer 7

infectious endocarditis and connective tissue disease

Question 8

the majority of mitral stenosis cases are due to what?

Answer 8

rheumatic heart disease

Question 9

why does rheumatic fever cause rheumatic heart disease?

Answer 9

cross-reactivity: same antibody binds both cardiac muscle sarcolemma and part of the cell wall of the streptococcus.

Question 10

what is the classic myocardial lesion in acute rheumatic fever?

Answer 10

aschoff body.

Question 11

what gross pathological changes are seen with chronic rheumatic heart disease?

Answer 11

fibrosis, thickening, shortening, fusion of the leaflets and chordae

Question 12

what effect does a mitral valve narrowing/stenosis have on the LV?

Answer 12

reduced LV filling, leads to decr SV and CO.

Question 13

how is the reduced LV filling in mitral stenosis compensated for?

Answer 13

by the LA, which enlarges to produce a diastolic gradient across the valve. causes pulm venous congestion –> HTN, edema, ultimatel right heart failure.

Question 14

what would be the systemic symptoms associated with mitral stenosis?

Answer 14

• long time of mild dyspnea, then rapid downhill course as mitral valve area decreases.
• dyspnea, orthopnea, fatigue

Question 15

what cardiac signs would you see/hear with mitral stenosis?

Answer 15

crackles, loud S1, mitral valve opening snap (OS),

Question 16

with mitral stenosis, what would you see on CXR?

Answer 16

increased LA size, increased RV size. normal LV.

Question 17

with mitral stenosis, what drug therapy might be suggested?

Answer 17

diltiazem (ca blocker), or metoprolol to slow HR and lengthen diastolic filling time. diuretics for heart failure.

Question 18

a few causes of mitral valve regurg?

Answer 18

• rheumatic heart disease
• mitral valve prolapse
• ischemia
• infective endocarditis

Question 19

rheumatic mitral regurg: pathology

Answer 19

fibrous contractures prevent leaflets from closing together. calcification around commissures.
LV hypertrophy and LAE.

Question 20

rheumatic mitral regurg: pathophysiology

Answer 20

systolic regurg into LA. volume overload of LV. may lead to LV failure, inc pulm pressures.

Question 21

rheumatic mitral regurg: general clinical findings

Answer 21

heart failure

Question 22

rheumatic mitral regurg: heart sounds

Answer 22

S1 normal (as opposed to mitral stenosis where S1 is loud). S3 gallop

Question 23

rheumatic mitral regurg: CXR

Answer 23

LVE, LAE

Question 24

rheumatic mitral regurg: drug therapy

Answer 24

diuretics, ACE inhbitors, digigalis.

Question 25

types of non-rheumatic mitral valve regurg?

Answer 25

• mitral valve prolapse

- ischemia

Question 26

mitral valve prolapse: pathology

Answer 26

myxomatous degeneration of valve tissue. may be associated with Marfan’s. lots of valve tissue/redundant. elongated chordae

Question 27

mitral valve prolapse: hallmark sound

Answer 27

mid-systolic click

Question 28

ischemic heart disease/mitral regurg: pathology

Answer 28

papillary muscle rupture/dysfunction

Question 29

ischemic disease/CHRONIC mitral regurg: pathophys

Answer 29

systolic regurg into LA. volume overload of LV. may lead to LV failure, inc pulm pressures.

Question 30

rupture of an entire papillary muscle during MI usually leads to what?

Answer 30

death

Question 31

Acute mitral regurg: LV size, LA size, LA pressure?

Answer 31

LV size normal, LA size normal, LA pressure high

Question 32

Chronic mitral regurg: LV size, LA size, LA pressure?

Answer 32

LV eccentric hypertrophy, LA enlarged, LA pressure normal/slightly elevated