CPR 8.03 Pathophysiology of Valve Disease

Question 1

Describe aortic stenosis and the common etiology.

Answer 1

inability of the aortic valve to fully open; usually caused by thickened, calcified leaflets.

Question 2

Describe the gross and microscope pathology seen in aortic stenosis

Answer 2

3. Gross Pathology: often bicuspid aortic valve. Calcified leaflets.
4. Microscopic Pathology: Marked calcification in the fibrosa layer of valve. Intact endothelial layer. P. 19

Question 3

Discuss pressure gradients, murmurs, SV and ESV, LVEDP and PCWP, and LVH in aortic stenosis

Answer 3

1. Large systolic gradient across aortic valve.
2. Systolic ejection murmur with S4 heart sound.
3. Decreased SV and Increased ESV.
4. Increased LVEDP and Increased PCWP.
5. LVH Ventricular concentric hypertophy (decreased LV compliance; diastolic dysfunction).
6. Large increase in myocardial O2 demand. (increased systolic wall shear)

Question 4

Define mitral stenosis and the most common causes.

Answer 4

: inability of mitral valve to fully open, usually caused by thickened, calcified leaflets
A. Pathology
1. Etiology: most common cause is chronic rheumatic fever and resulting inflammatory responses. Can also be congential or age related calcification.

Question 5

Describe the gross and microscopic pathology seen in mitral stenosis.

Answer 5

3. Gross Pathology: Stiff, thickened valve, Fusion of leafles and chordae. P. 32
4. Microscopic Pathology: fibrosis. No inflammatory cells present in chronic condition. P. 34.

Question 6

Describe the pressure gradient, murmur, LVEDV and SV, and PCWP in mitral stenosis

Answer 6

1. Increased Pressure gradient across mitral valve during diastole.
2. Diastolic murmur with opening snap.
3. Reduced LV filling (decreaed LVEDV) and decreased SV
4. Increased PCWP and enlarged LA, which can lead to pulmonary edema and atrial fibrillation.

Question 7

Define aortic regurgitation and the types of causes.

Answer 7

improper aortic valve closure causing backward leakage of blood into the LV during ventricular relaxation.
A. Pathology
1. Etiologies: leaflet abnormalities, Dilation of aortic root (aneurysm/dissection).

Question 8

Discus physiologic changes seen in aortic regurgitation: PP, ventricle size, SV and aortic SV, murmur, LVEDP and PCWP, wall stress

Answer 8

1. Large aortic pulse pressure (increased systolic P, decreased diastolic P)
2. Ventricular dilation (large increase in EDV) and eccentric hypertrophy (also LA eccentric hypertrophy).
3. Large increase in left ventricular SV although net forward flow into aorta may be reduced.
4. Diastolic murmur (decrescendo)
5. No isovolumetric relaxation or contraction.
6. Increased LVEDP and Increased PCWP (though chronic dilation and subsequent increase in compliance attenuates this)

Question 9

Define mitral regurgitation and the types of causes

Answer 9

mproper mitral valve closure causing backward leakage of blood (regurgitation) into the LA during ventricular contraction.
A. Pathology
1. Etiology: annular calcification, Leaflet disorders, Chordae tendinae/papillary dysfunction, LV dilatation.

Question 10

Describe the gross and microscopic pathology seen in mitral regurgitation

Answer 10

3. Gross Pathology: billowing prolapse with dilated valve annuls and white colored valve.
4. Microscopic Pathology: myxomatous CT in center of leaflet due to excess dermatan sulfate production.

Question 11

Discus physiologic changes seen in mitral regurgitation: PPventricle size, SV and aortic SV, murmur, atrial distension and PCWP, wall stress

Answer 11

1. Ventricular dilation (Large increase in EDV; eccentric hypertrophy).
2. Large increase in SV (EDV-ESV) with decreased SV into aorta.
3. Atrial distension and Increased PCWP.
4. Tall v-wave.
5. Holosystolic murmur.
6. No isovolumetric relaxation or contraction.
7. Increased myocardial oxygen demand. (may be offset in decreaed aortic pressure).

Question 12

What is a mitral valve prolapse and what can cause this?

Answer 12

billowing up of leaflet, most often osterior, during contraction. Associated with mid-systolic click followed by systolic murmur
1. Casued by degernative valve disease (fibroelastase deficiency), Barlow’s disease (Classiv MVP in young fmeales), Marfan, ruprtured chordae or pap.

Question 13

What valves are most commonly involved in chronic rheumatic fever? How do they look?

Answer 13

1. Rheumatic Heart Disease can cause mitral stenosis. May also affect aortic valve.
2. Typically will see fibrous thickening of leaflets with commissural fusion.