L29. Valve Diseases

Question 1

What is Stenosis?

Answer 1

A narrowing of the valve leading to a restriction of flow
Causes a pressure gradient across the valve
Increase in the pressure chamber behind it
= PRESSURE OVERLOAD

Question 2

What is Regurgitation?

Answer 2

A leaky or incompetent valve that doesn’t close fully. Blood leaks back into the previous chamber.
The heart is required to pump a higher SV in order to maintain the same overall CO. (Leads to increased ESV) and increased ejection fraction
= VOLUME OVERLOAD

Question 3

How do we diagnose valve diseases by clinical examinations?

Answer 3

Stenosed and incompetent valves cause TURBULENT blood flow which can be heard as murmurs.

Question 4

Are all murmurs pathogenic?

Answer 4

NO - some are benign and can occur in high flow/high output states like in children, fever, anaemia and pregnancy

Question 5

What are the major causes of valvular heart disease?

Answer 5

Rheumatic Fever (decreasing incidence in western countries)
Degenerative conditions
Congenital diseases

Question 6

Are all valvular diseases symptomatic?

Answer 6

No: mild and moderate lesions are asymptomatic because cardiac compensation is very effective for many years

Question 7

What happens when cardiac compensation for valvular disease begins to fail?

Answer 7

Ventricular enlargement and irreversible failure of the heart (loss of contraction)
Symptoms present: Eg. Shortness of breath
Other irreversible changes to the heart occur

Question 8

What is the Gold Standard Assessment Method for diagnosis of valvular disease?

Answer 8

Echocardiography - gives diagnosis, severity, ventricular size and function, atrial size, pulmonary artery pressure
- can show LV changes before they are irreversible

Question 9

What are the major interventions for valve diseases?

Answer 9

Heart Valve replacements (metal, plastic, bioprosthesis, stents)
Valve repairs
Balloon valvotomy

Question 10

Describe aortic stenosis

Answer 10

Progressive narrowing of the aortic valve that can lead to fibrosis and calcification
Reduced area 2.5)

Leads to an increased pressure in the heart: PRESSURE OVERLOAD and subsequent concentric hypertrophy. The increased LVEDP and atrial kick are important

Question 11

What kind of murmur is heard in aortic stenosis?

Answer 11

Blood cannot get out of the heart easily and thus turbulent flow during ejection/systole
= SYSTOLIC MURMUR (crescendo, decrescendo harsh and rough sound)

Question 12

What are the outcomes of aortic stenosis?

Answer 12

Usually calcification and is often well tolerated with no symptoms until severity increases to a point where surgical intervention is required.

Question 13

Describe aortic Regurgitatoin

Answer 13

When the aortic valve is damaged in a way that means it is unable to close.

Leads to an increase in the volume of the ventricle: VOLUME OVERLOAD and subsequent eccentric hypertrophy. The EDP and the EF increase to compensate and maintain an normal SV

Question 14

What are some causes of Aortic regurgitation?

Answer 14

Damage of the valve itself (endocarditis, rheumatic fever), aortic root dilation (Marfan’s syndrome, aortic dissection, collagen disorders

Question 15

What kind of murmur is heard in aortic regurgitation?

Answer 15

There are problems in keeping the valve shut when it needs to me (diastole) and hence there is a diastolic murmur heard: “Whoosh” sound heard just after S2
and End Diastolic Murmur

Question 16

What are the outcomes of aortic regurgitation?

Answer 16

Increased Pulse Pressure: Bounding pulse
Often well tolerated without symptoms until decompensation where LV function decreases due to the overload of volume and inability to increase EDP to maintain CO (cardiac failure)

Question 17

Describe Mitral Valve Regurgitation

Answer 17

When the mitral valve doesn’t close properly (leakage during systole back into the atria) which leads to a VOLUME OVERLOAD and subsequent concentric hypertrophy of the atria (not as much as a ventricular hypertrophy)

This increases the EDV and increases EF to compensate

Question 18

What are some causes of mitral valve regurgitation?

Answer 18

Myxomatous degeneration is the commonest cause (prolapse of the valves with age)
Ruptured chorda tendinae
Infective endocarditis
Myocardial Infarction: ruptured papillary muscle
Rheumatic fever
Collagen vascular diseases
Cardiomyopathy

Question 19

What are the outcomes of mitral regurgitation?

Answer 19

Generally well tolerated until decompensation occurs leading to increased LV diastolic volume.
Atrial fibrillation
Thrombus formation can occur in the LA due to accumulated blood
Pulmonary hypertension due to increased back pressure

Question 20

What kind of murmur is heard as a result of mitral regurgitation?

Answer 20

The valve is not able to keep closed during systole and turbulent back flow into the atrium occurs and so a systolic murmur is heard.
It is a pansystolic sound (same the whole way through systole)

Question 21

Describe Mitral Stenosis

Answer 21

A progressive narrowing of the mitral valve meaning problems with filling (diastole) and higher pressures need to be made by the atrium (atrial kick) to fill the ventricle (ventricle systolic function is not affected)

Question 22

What are the causes of mitral valve stenosis

Answer 22

Most often due to preveious rheumatic fever that causes a fibrotic narrowing of the mitral valve

Question 23

What is the right atrial response to mitral valve stenosis?

Answer 23

Increase in both the pressure and volume in the right atrium which is a risk of fibrillation and thrombus formation.

Increased pulmonary venous pressure leading to pulmonary congestion, oedema and hypoxia leading to pulmonary hypertension

Question 24

What are the outcomes of mitral valve stenosis?

Answer 24

Well tolerated if mild or moderate but decompensation leads to pulmonary hypertension and other problems.

Question 25

For valve problems, what does the onset of symptoms usually coincide with?

Answer 25

A need for surgical intervention

Question 26

What kind of murmur is heard during mitral valve stenosis?

Answer 26

There is a problem with diastole (filling of the heart) with turbulent flow through it causing a low pitched diastolic sound