3.6 Pathophysiology of Valvular Disease

Question 1

In terms of heart valve layers, the ___ is where the blood is coming from, and the ___ is where it’s going to, and the ___ is in the middle

Answer 1

• Ventricularis
• Fibrosa
• Spongiosa

Question 2

What are the four most common left-sided valvular pathologies?

Answer 2

• Aortic stenosis/regurguitation
• Mitral stenosis/regurgitation

Question 3

Mitral stenosis influence on pressure/volume loop

Answer 3

• Decreased stroke volume; mitral valve closes at lower volume
• LV can still produce enough pressure, and can relax enough at diastole
• Shifted left and thinner

Question 4

Why does end diastolic volume dramatically increase during mitral regurgitation

Answer 4

The left ventricle dilates in response to the regurgitation so that ventricular compliance increases.

Question 5

Why does systolic pressure decrease during mitral regurgitation

Answer 5

Due to leaky valve, not as much pressure can be produced as normal

Question 6

Why does the heart often fail after a period of mitral regurgitation

Answer 6

• Over time, the end-systolic volume starts to increase
• This results in decreased stroke volume

Question 7

How can aortic stenosis lead to heart failure?

Answer 7

• LV needs to generate increased pressure in order to pump blood during systole
• Results in LV hypertrophy
• LV becomes less able to relax; decreased filling capacity during diastole

Question 8

How can aortic regurgitation lead to heart failure

Answer 8

• Blood flows back into LV from aorta
• Heart compensates by increasing stroke volume
• Over time, stroke volume approaches zero
• Heart failure

Question 9

Back-flow related symptoms of left sided valvular pathology

Answer 9

• Dyspnoea
• Peripheral oedema
• Palpitations

Question 10

Forward-flow related symptoms of left sided valvular pathology

Answer 10

• Fatigue
• Syncope/presyncope
• Angina

Question 11

Back-flow related signs of left sided valvular pathology

Answer 11

• Fine crepitations
• Irregular pulse
• Displaced apex beat
• Elevated JVP
• Ankle oedema

Question 12

Foward-flow related signs of left sided valvular pathology

Answer 12

• Pulse pressure (AR/AS)
• Low blood pressure
• Low urine output
• Peripheral cyanosis

Question 13

Why does pulse pressure widen during AR and decrease during AS?

Answer 13

AR: During diastole, blood flows back into the ventricles, resulting in decreased diastolic pressure; systolic pressure is normal or sometimes elevated, thus increased pulse pressure.

AS: Less blood than usual can move across the aortic valve, meaning the pressure difference between systole and diastole decreases

Question 14

List some causes of regurgitant valvular heart disease

Answer 14

• Congenital conditions
• Perforation of valves
• Paravalvular
• Cleft in valve

Question 15

List some causes of stenotic valvular disease

Answer 15

• Congenital
• Calcific/fibrotic (age; such as rheumatic heart disease)
• Sub/supravalular; the bit before or after the valve

Question 16

Primary causes of valvular disease (leaflet/cord)

Answer 16

• Rheumatic heart disease (most common)
• Degenrative/calcific
• Endocarditis
• Connective tissue disease

Question 17

Secondary causes of valvular disease (chamber issues)

Answer 17

• Annular dilation
• Leaflet restriction