Valvular Heart Disease *

Question 1

What is the most common cause of mitral valve stenosis?

Answer 1

Rheumatic fever

Question 2

What happens when mitral valve stenosis occurs?

Answer 2

The valve leaflets are calcified and thicken. The cordinaea tendon a get thicker and shorter. And there is fusion of the leaflet borders.

Question 3

What is passive hypertension?

Answer 3

It’s when there’s backward transmission of elevated left atrial pressure into the pulmonary vasculature.

Question 4

What is reactive hypertension?

Answer 4

It’s when there’s medial hypertrophy and intimal fibrosis of pulmonary arterioles.

Question 5

Why is reactive hypertension beneficial?

Answer 5

It protects the capillaries from excessively high pressure since it prevents blood flow into the congested capillary bed. However, this can lead to right-sided heart failure

Question 6

Chronic pressure overload of the LA leads to what?

Answer 6

Atrial enlargement, aka dilation.

Question 7

What happens when atrial enlargement occurs?

Answer 7

It stretches the conduction fibres leading to atrial fibrillation.

Question 8

What happens when atrial fibrillation occurs?

Answer 8

There’s a decline in CO as diastole is shortened. There’s also less time for blood to flow across the mitral valve to fill the LV, further increasing LA pressure.

Question 9

What are the consequences of stroke volume being ejected backwards into the left atrium during systole?

Answer 9

1. Elevated LA volume and pressure.
2. reduced cardiac output
3. volume overload of LV

Question 10

What are the 5 factors that determine mitral regurgitation severity and the ratio of forward:backward flow?

Answer 10

1. Size of mitral orifice
2. Pressure Gradient between LV and LA during systole.
3. Systemic Vascular Resistance
4. LA compliance
5. Duration of regurgitation with each contraction

Question 11

What’s the regurgitation fraction?

Answer 11

Volume of mitral regurgitation/volume of LV stroke volume

Question 12

When does the regurgitation fraction rise?

Answer 12

When there’s aortic stenosis or systemic Vascular resistance.

Question 13

LA pressure rise is a function of what?

Answer 13

LA compliance

Question 14

What is acute regurgitation?

Answer 14

Sudden rupture of chordae tendineae, which leads to a lack of time for LA to adapt to regurgitation. It can also lead to pulmonary congestion.

Question 15

What’s chronic regurgitation?

Answer 15

It’s the gradual development of regurgitation. It permits LA to dilate and lessen the effects of regurgitation on pulmonary congestion.

Question 16

Stagnant blood in left atrium during chronic LA pressure overload leads to what?

Answer 16

Intro-atrial thrombus formation.

Question 17

What causes aortic stenosis?

Answer 17

Age related calcific changes of the valve or congenitally deformed aortic valves. (Aortic sclerosis)
Years of turbulent flow also disrupts the endothelial and collagen matrix.

Question 18

Significant rise in LV pressure occurs when the orifice is reduced by more than ___ ?

Answer 18

50%

Question 19

What are the manifestations of aortic stenosis?

Answer 19

1. Angina
2. Exertional Syncope
   (CO unable to increase during exercise coupled with peripheral vasodilation - reduction in BP)
3. Symptoms of Heart Failure
   (Late stages of AS result in significantly elevated LA pressure leading to pulmonary congestion)

Question 20

What causes aortic regurgitation?

Answer 20

Diseases of the aortic leaflets and dilation of the aortic root.

Question 21

What causes the severity of aortic regurgitation?

Answer 21

1. Size of the regurgitant aortic orifice
2. The pressure gradient across the aortic valve during diastole
3. The duration of diastole

Question 22

What causes acute aortic regurgitation?

Answer 22

Regurgitation that results in high LV diastolic pressure which is transmitted to the LA and pulmonary edema.

Question 23

What’s chronic aortic regurgitation characterized by?

Answer 23

LV under volume and pressure load and compensates through dilation and eccentric hypertrophy, and also concentric hypertrophy to a lesser degree.

Question 24

What happens overtime with left ventricular remodelling?

Answer 24

Overtime it leads to systolic dysfunction. There’s also an increase in left atrial and pulmonary Vascular pressures.