Mitral Stenosis, Mitral Regurgitation, Aortic Valve Stenosis, Aortic Valve Regurgitation (pathology)

Question 1

What is mitral stenosis?

Answer 1

Mitral valve orifice <2cm^2

Question 2

What is the pathophysiology of mitral stenosis (5)?

Answer 2

• ↑ AV pressure
• ↑ LA pressure
• Pulmonary hypertension
• ↑ TPR
• Right Heart dilatation + tricuspid & pulmonary regurgitation

Question 3

What are the symptoms of mitral stenosis (6)?

Answer 3

• SOB due to pulmonary oedema
• Haemoptysis due to thin-walled veins rapture
• Left atrium and atrial appendage enlargement leading to systemic emboli
• Infective endocarditis
• Chest pain
• Hoarseness due to compression of recurrent laryngeal nerve by enlarged LA

Question 4

What are the signs of mitral stenosis (7)?

Answer 4

• Mitral facies (purple discoloration of cheeks and nose)
• Normal pulse
• Prominent JVP
• Tapping apex beat
• Diastolic thrill
• Right ventricle heave
• Diastolic murmur – opening snap-> ↑ pressure gradient LA-LV

Question 5

What are the investigations for Mitral stenosis? (What can be seen from these investigations?)

Answer 5

ECG 
-	Signs of right ventricular hypertrophy 
-	Taller R waves in V1 V2 
-	LA enlargement P > 0.12 sec
Cardiac catheterisation 
– determine LA pressure indirectly
CXR 
-	Left atrium enlargement -> straight left heart border 
Echo 
-	Thickening + scarring of leaflets 
-	Fusion of commissures 
-	‘elbowing’ of anterior leaflet 
-	Velocity of transmitted flow at rest & exercise-> determine severity of MS 
MRI 
-	Enlarged LA

Question 6

What is the medical treatment for mitral stenosis?

Answer 6

• Diuretics + restrict salt
• Restore sinus rhythm in AF
• Anticoagulation-> stroke prevention

Question 7

What is the surgical treatment for mitral stenosis?

Answer 7

• Valvotomy

- Mitral valve replacement if MVA on echo < 1.5 cm2

Question 8

What is the difference between a biological and mechanical valve replacement? How does the follow up treatment differ?

Answer 8

Biological valve= no warfarin but worn-out valve after 15 years –ELDERLY
Mechanical valve= warfarin for life, valve lasts > 40 years – YOUNG

Question 9

What is mitral regurgitation?

Answer 9

Leaky valve

Annular enlargement—> ↑ regurgitant volume—> LV compensation

Question 10

What is acute vs chronic Mitral regurgitation?

Answer 10

Acute= heart contracts more forcefully= ↓ESV and ↑ESP 
Chronic= ↑EDV, normal ESV , ↑↑ contractility= LEFT VENTRICULAR HYPERTROPHY

Question 11

What is the aetiology of mitral regurgitation (4)?

Answer 11

• Rheumatic heart disease
• Mitral valve prolapse – Myxomatous degeneration
• Infective endocarditis
• Functional mitral regurgitation due to enlarged LV and annular dilatation

Question 12

What are the causes of acute mitral regurgitation (2)?

Answer 12

Valve perforation

Chordal/papillary muscle rupture

Question 13

What are the symptoms of acute mitral regurgitation?

Answer 13

EMERGENCY!

• SOB due to pulmonary oedema and Cardiogenic shock
• decreased BP & very high Heart rate

Question 14

What are the symptoms of chronic mitral regurgitation (3)?

Answer 14

• Fatigue, exhaustion due to ↓CO
• Right heart failure
• SOB or palpitations due to AFib

Question 15

What are the signs of mitral regurgitation (7)?

Answer 15

• Normal pulse or reduced in HF
• Prominent JVP if RH failure
• Brisk and hyperdynamic apex beat
• RV heave (abnormally large beating heart)
• Reduced S1 because valve leaflets cannot find each other
• Holosystolic murmur of MR- radiates to axilla
• Split S2: early A2, loud P2

Question 16

What investigations for mitral regurgitation? (What would they show)

Answer 16

ECG
- Left Atrial enlargement P> 0.12 sec
- Right ventricular hypertrophy tall R waves in V1 V2
CXR
- Cardiomegaly, LA enlargement, mitral annulus calcification
Transoesophageal echo
- Assess LV dimensions
- Identify causes of MR (leaflet dysfunction, rapture of chordae/papillary muscles
- Assess disease severity with Pulmonary arterial pressure-> prognostic indicator
MRI
- Accurate cardiac volumes
- Volumetric determination of regurgitant volume

Question 17

What is the medical treatment for acute mitral regurgitation?

Answer 17

Acute MR 
-	Reduce preload / afterload 
	•	SODIUM NITROPRUSSIDE – vasodilator 
	•	DOBUTAMINE ↑↑contractility 
	•	Intra-aortic balloon pump = ↑↑CO

Question 18

What is the medical treatment for chronic mitral regurgitation?

Answer 18

• No therapy helps with haemodynamic

- Preserve LV functio

Question 19

What are the surgical treatments for mitral regurgitation?

Answer 19

• Mitral valve repair or replacement
• Repair> replacement
• Replacement if severe MVR with blood flow into pulmonary v. on echo

Question 20

What is aortic valve stenosis?

Answer 20

Normal AV area= 3-4 cm2

AV Stenosis < 1.5-2 cm2

Question 21

Rheumatic vs degenerative aortic valve stenosis?

Answer 21

Rheumatic:
- Fusion of commissures and retraction/stiffening of free cusp margins
Degenerative:
- Due to atherosclerosis, slow inflammatory process, calcification of cusps

Question 22

What is the pathophysiology of aortic valve stenosis?

Answer 22

↑↑ LV systolic pressure -> LV hypertrophy -> ↑↑ Left ventricular end diastolic pressure ↑↑ LA pressure
Pulmonary hypertension
↑↑ myocardial O2 use -> ischemia-> LV failure

Question 23

What is the aetiology of aortic valve stenosis?

Answer 23

• Degenerative Most common
• Rheumatic
• Bicuspid AV – congenital abnormality- 2 leaflets instead of 3

Question 24

What are the symptoms of aortic valve stenosis?

Answer 24

• Long asymptomatic phase
• Severe symptoms
  • Angina
  • Syncope/dizziness due to ↓ CO
  • SOB on exertion
  • HF

Question 25

What are the signs of aortic valve stenosis (7)?

Answer 25

- Small volume pulse- slowly rising - JVP if RHF - Low BP - Vigorous sustained apex beat - RV heave - End systolic murmur-radiate to carotids - normal S1 + less audible A2 because of murmur (differentiate from aortic sclerosis)

Question 26

What are the investigations for aortic valve stenosis?

Answer 26

``` Echo - Demonstrate AV cusp mobility - LV function and hypertrophy - Doppler =determine velocity of blood ejected from LV into aorta—> indirectly determine AV area Cardiac MRI ```

Question 27

What are the medical and surgical treatments for aortic valve stenosis?

Answer 27

Medical - Limited to those that develop HF Surgical - Aortic valve repair or replacement

Question 28

What is aortic valve regurgitation?

Answer 28

LV receives systolic volume + regurgitant volume —> ↑↑ LV EDV and LV systolic pressure —> LV hypertrophy + dilatation —> ↑↑ myocardial O2 use—> ischaemia—> LV failure

Question 29

What is the aetiology of aortic valve regurgitation?

Answer 29

``` Can be due to defect in: - Aorta • Dilated aorta (Marfan’s, hypertension) - Leaflets: • Bicuspid aortic valve • Rheumatic heart disease • Endocarditis • Myxomatous degeneration ```

Question 30

What are the symptoms of acute and chronic aortic valve regurgitation?

Answer 30

``` Acute AR – EMERGENCY - ↑↑ wall tension Chronic AR - Long asymptomatic phase - Exertional breathlessness ```

Question 31

What are the signs of aortic valve regurgitation?

Answer 31

- Large volume collapsing pulse – CORRIGAN SIGN - Wide pulse pressure ↑↑ systolic ↓diastolic - hyperdynamic displaced apex beat - Early diastolic murmur – difficult to hear- ask patient to lean forward

Question 32

What are the investigations for aortic valve regurgitation? (What would they show?

Answer 32

ECG - ST changes due to LV strain, left axis deviation due to left ventricle hypertrophy CXR - Cardiomegaly in chronic AR *Cardiac catheterisation- obsolete Echo - AV cusp anatomy - LV function, dilatation, and hypertrophy - Doppler assessment of regurgitant flow = ↑↑ pressure difference between systole and diastole= ↑↑ severity MRI

Question 33

What are the medical and surgical therapies for aortic valve regurgitation?

Answer 33

Medical - Vasodilator therapy Surgical - AV repair (rare) or replacement in severe AV regurgitation with LV dilatation