Valvular Heart Disease- pathophysiology..

Question 1

How many leaflets does mitral valve have?

Answer 1

2

Question 2

Causes of mitral valve stenosis?

Answer 2

cause- rheumatic heart disease, congenital, SLE or RA

Question 3

Characteristics of mitral stenosis?

Answer 3

MV orifice <2cm squared
increased gradient between atrium and ventricle
increase in LA pressure
pulmonary venous and capillary pressures increase
Increase in pulmonary vascular resistance
increase in pulmonary artery pressure and pulmonary hypertension
Right heart dilatation with tricuspid regurgitation and pulmonary regurgitation

Question 4

What does M stenosis severity depend upon?

Answer 4

trans-valvular pressure gradient
trans-valvular flow rate (depends on blood volume and heart rate)

Question 5

What clinical conditions are dangerous for MS?

Answer 5

exercise
acute illness
pregnancy
a fib

Question 6

What are the clinical manifestations of mitral stenosis?

Answer 6

shortness of breath - due to pulmonary oedema
haemoptosis- rupture of thin walled veins
systemic embolisation- LA and LAA enlargement (clots)
Infected valve
chest pain
hoarseness from compression of L recurrent laryngeal nerve

Question 7

Clinical examination of mitral stenosis?

Answer 7

mitral facies - purple discoloration
pulse normal
JVP- can be elevated
Tapping apex beat and diastolic thrill
RV heave
Ausculation- loud snapping first heart sound
loud opening snap after second heart sound
turbulent flow through narrowed valve creates low pitched, rumbling murmur

Question 8

What are the investigations of mitral stenosis?

Answer 8

Echocardiography- thickening and scarring of leaflets, fusion of the commissures

ECG - RVH , elongated P wave> 0.12 seconds

CXR- left atrial enlargement

Question 9

Medical treatment for MS?

Answer 9

Anticoagulation: for all those with AF
Diuretics
restriction of Na intake
A fib: Restore sinus rhythm or rate of heart
Anticoagulation: for all those with AF

Question 10

Interventional treatment of mitral stenosis?

Answer 10

valvotomy
mitral valve replacement

Question 11

What is mitral regurgitation?

Answer 11

leaky valve

Question 12

Reasons for mitral regurgitation?

Answer 12

rheumatic mitral valve disease
mitral valve prolapse
infected endocarditis
degenerative
function mitral regurgitation due to lV and annular dilatation

Question 13

Pathophysiology of mitral regurgitation?

Answer 13

the effective regurgitant orifice (ERO) is the area through which blood leaks backward - depends on preload, afterload and LV contractility

Question 14

Compensation method of acute MR?

Answer 14

No time for compensation.

Small LA → sharp rise in LA pressure → pulmonary edema.

LV ejects blood both forward and backward → low forward output, decreased end-systolic volume (ESV).

Question 15

Compensation method of chronic MR?

Answer 15

Gradual compensation over time.

LA dilates to absorb regurgitant volume → normalizes pressure early on.

LV dilates and hypertrophies eccentrically → increased EDV maintains stroke volume.

Eventually leads to LV dysfunction and heart failure when decompensation occurs.

Question 16

Clinical manifestations of acute MR and chronic MR?

Answer 16

acute: act quicky
happens because of valve perforation or chordal/ papilary muscle
present with breathlessness, pulm oedema , cardiogenic shock

chronic:
fatigue, exhaustion, right heart failure
dyspnoea or palpitations due to A fib

Question 17

Clinical examination of mitral regurgitation?

Answer 17

pulse- normal or reduced due to HF
increased JVP
brisk and hyperdynamic apex beat
RV heave
Auscultation: reduced first heart sound, second heart sound split, early A2, loud P2.
Holosystolic, blowing, loud at apex, radiating to axilla

Question 18

Investigations for mitral regurgitation?

Answer 18

Echocardiography: Can see LV dimensions, can see if due to leaflet dysfunction, chordae, papillary muscles or annular disease. Shows severity of MR and pulmonary arterial pressure

Cardiac magnetic resonance:
accurate cardiac volumes and volumetric determination of regurgitant volume
ECG: LA enlargement (P>0.12 sec,tall) RVH (prominent R wave in R pre cordial leads)

CXR- cardiomegaly, LA enlargement, calcification of mitral annulus

Cardiac catheterisation: LV angiography

Question 19

Medical treatment of Acute MR and chronic MR?

Answer 19

Acute MR: preload and afterload reduction
give vasodilators like sodium nitroprusside, increase contractility with dobutamine and insert aortic balloon pressure

chronic MR: lack of evidence that any therapy is beneficial for hemodynamic improvement

• refer them to interventional treatment- repair of mitral valve apparatus or replacement

Question 20

Normal aortic valve area?

Answer 20

3-4 cm

Question 21

Causes of aortic stenosis?

Answer 21

degenerative
rheumatic
biscuspid abnormality instead of tricuspid

Question 22

Describe the rheumatic cause?

Answer 22

adhesion, fusion of commissures and retraction and stiffening of the free cusp margins

Question 23

Describe the degenerative cause?

Answer 23

linked to atherosclerosis, a slow inflammatory process resulting in thickening and calcification of the cusps from base to free margins

Question 24

What happens in aortic valve stenosis?

Answer 24

increased lv systolic pressure - severe concentric hypertrophy and increase in LV mass- increase left ventricular end diastolic pressure - increase in myocardial oxygen consumption- leading to myocardial ischaemia - LV failure

Question 25

Aortic stenosis symptoms?

Answer 25

long asymptomatic phase chest pain dizziness breathlessness on exertion HF

Question 26

Clinical examination of aortic stenosis?

Answer 26

pulse- small volume and slowly rising JVP- prominent if RH failure present, low BP vigorous and sustained apex beat RV Heave Auscultation- hear first heart sound, systole occupied by loud harsh murmur that radiates to carotifs, harder to hear second

Question 27

Aortic stenosis investigations?

Answer 27

ECG for LVH voltage criteria and ST/T changes Echocardiography: demonstrates AV cusp mobility, Lv function and hypertrophy and derive aortic valve area

Question 28

Who gets treatment for aortic stenosis?

Answer 28

limited to those who develop HF interventional treatment: aortic valve replacement or repair

Question 29

Causes of aortic regurgitation?

Answer 29

aorta: dilated aorta (marfans, hypertension) connective tissue disorders leaflets bicuspid aortic valve rheumatic heart disease endocarditis myxomatous degeneration

Question 30

Pathophysiology of aortic regurgitation?

Answer 30

LV accommodates both stroke volume and regurgitant volume- leads to increase in LV-EDV and LV- systolic pressure- Left ventricle will undergo hypertrophy and dilate- increase myocardial oxygen consumption - myocardial ischaemia and LV failure

Question 31

Symptoms of aortic regurgitation?

Answer 31

Chronic AR - long asymptomatic -exertional breathlessness Acute AR - poorly tolerated as wall tension cannot acutely adapt (LV pressure x LV radius/ wall thickness)

Question 32

Clinical examination of aortic regurgitation?

Answer 32

pulse- large volume and collapsing wide pulse pressure- systolic pressure high and diastolic low because a lot of ejected volume in aorta will return back in ventricle- aortic diastolic pressure low apex beat hyperdynamic and displaced auscultation: normal first heart sound , normal second and flowwed by early diastolic, soft murmur

Question 33

Laboratory investigations for aortic regurgitation?

Answer 33

ECG-ST/T changes (LV strain), LAD CXR - cardiomegaly in chronic AR Echocardiography: demonstrates the AV cusp anatomy , LV function, and can see haemodynamic assessment of regurgitant flow

Question 34

Treatment for aortic regurgitation?

Answer 34

vasodilator shown to delay timing for surgical intervention interventional: aortic valve replacement or repair