51 - Cardiac Valve Dysfunction

Question 1

Answer 1

Question 2

Proportion of heartbeat that is systole and is diastole

Answer 2

~1/3 is systole, ~2/3 is diastole (diastole is longer)

Question 3

Effect of valve stenosis 1) 2) 3)

Answer 3

1) Valve doesn’t open fully, restricting flow. 2) Higher pressure in chamber behind valve (EG: LV in aortic stenosis, LA in bicuspid stenosis) 3) Pressure overload

Question 4

Valve incompetence

Answer 4

Valve leaking/regurgitation. Where valve doesn’t close properly, causing leak of blood back.

Question 5

Effect of valve incompetence

Answer 5

Heart required to increase stroke volume to maintain forward cardiac output. Increased volume in ventricle increased EDV. This increases ejection fraction and preload.

Question 6

What used to be most common cause of valve disease?

Answer 6

Rheumatic fever

Question 7

Current most common cause of valve disease

Answer 7

Degenerative conditions

Question 8

When do valve lesions become symptomatic

Answer 8

When they are quite severe. Mild and moderate lesions are asymptomatic

Question 9

When do symptoms develop in valve regurgitation?

Answer 9

Late stage. Occur when irreversible LV changes occur (ventricular enlargement, decompensation).

Question 10

When do symptoms present in aortic stenosis?

Answer 10

Before permanent LV changes

Question 11

How is valvular heart disease assessed? 1) 2) 3) 4)

Answer 11

1) History (especially shortness of breath, which presents in late stage, is poo prognosis) 2) Examination (murmur, pulse) 3) ECG 4) Echocardiography (most important test)

Question 12

Types of prosthetic valves 1) 2) 3) 4)

Answer 12

1) Mechanical valve 2) Bioprosthetic valve 3) Repaired mitral valve 4) Stent aortic valve

Question 13

Procedure than can fix a stenosed valve

Answer 13

Balloon valvotomy (insert balloon catheter into valve, inflate to break up stenosis).

Question 14

Normal aortic valve area

Answer 14

2.5cm^2

Question 15

Severe aortic stenosis valve area

Answer 15

Under 0.7cm^2

Question 16

Normal pressure gradient across aortic valve

Answer 16

0mmHg

Question 17

Severe pressure gradient across a stenosed aortic valve

Answer 17

Over 50mmHg

Question 18

*Appearance of a Wigger’s diagram of a stenosed aortic valve

Answer 18

Note exaggerated LV systolic pressure

Question 19

Left ventricular response to aortic stenosis 1) 2) 3) 4) 5)

Answer 19

1) Concentric hypertrophy from pressure overload 2) Less compliant walls, as thicker 3) Diastolic dysfunction 4) Increased LVEDP required to fill LV 5) Atrial contraction becomes important to fill LV

Question 20

LV response to surgery for aortic stenosis

Answer 20

Often returns from concentrically-hypertrophied to normal

Question 21

What causes systolic murmurs?

Answer 21

Problems with either aortic or pulmonary valve

Question 22

Murmur sound of aortic stenosis

Answer 22

Crescendo-decrescendo. Pressure gradient rises and falls quickly during systole.

Question 23

Effects of aortic regurgitation 1) 2) 3) 4) 5)

Answer 23

1) To maintain normal cardiac output, LV needs to pump greater volume with each beat 2) Volume overload 3) Increased end diastolic volume 4) Increased ejection fraction 5) Normal end systolic volume

Question 24

*How does a Wigger diagram of aortic regurgitation appear?

Answer 24

Exaggerated LV systolic pressure and aortic pressure

Question 25

When do symptoms of aortic regurgitation present?

Answer 25

Often when irreversible decompensation occurs

Question 26

Effects of untreated aortic regurgitation 1) 2) 3)

Answer 26

1) LV diastolic volume increases a lot 2) LV function decreases 3) LV systolic volume increases

Question 27

Causes of mitral regurgitation 1) 2) 3) 4) 5) 6) 7)

Answer 27

1) Myxomatous degeneration (mitral valve prolapse) 2) Ruptured chordae tendinae (flail leaflet) 3) Infective endocarditis 4) Myocardial infarct (can rupture papillary muscle) 5) Rheumatic fever 6) Collagen vascular disease 7) Cardiomyopathy (change in ventricle shape)

Question 28

Effects of mitral regurgitation 1) 2) 3) 4) 5) 6)

Answer 28

1) To maintain CO, LV needs greater stroke volume 2) Volume overload 3) Increased end diastolic volume 4) Increased ejection fraction 5) Normal end systolic volume 6) Increased left atrial volume and pressure (same as with aortic regurgitation, except for left atrial change)

Question 29

Effects of decompensation from mitral regurgitation 1) 2)

Answer 29

1) Increase in LV diastolic and systolic volume (diastolic is more marked) 2) Reduced ejection fraction

Question 30

When do symptoms of mitral valve regurgitation appear?

Answer 30

When decompensation occurs. Changes irreversible

Question 31

Mitral systolic murmur 1) 2) 3)

Answer 31

1) From regurgitation 2) Pressure gradient between LA and LV appears 3) Pansystolic murmur, not crescendo-decrescendo like aortic stenosis murmur.

Question 32

Common cause of mitral stenosis

Answer 32

Rheumatic fever in women

Question 33

Effect of mitral stenosis 1) 2) 3) 4)

Answer 33

1) Reduced LV filling 2) LA contraction becomes more important in filling LV 3) LV systolic function not affected 4) Can lead to pulmonary artery hypertension

Question 34

*Appearance of a Wigger’s diagram with mitral stenosis

Answer 34

Elevated left atrial pressure

Question 35

How well is mitral stenosis tolerated?

Answer 35

Well, if mild to moderate

Question 36

Interventions for stenoses 1) 2)

Answer 36

1) Valvotomy 2) Valve replacement

Question 37

Possible causes of valve prolapse

Answer 37

Long chordae tendinae or valve leaflets