Valvular Heart Disease Flashcards
How are the valves arranged in the heart?
- Valves are situated within a 1cm line
- They sit at the ‘bases’ of the heart
Describe the anatomy of the mitral valve.
- Bicuspid valve with 2 cusps
- Anterior cusp is larger
- Posterior is more semi-lunar shaped
- Separates the left atrium and left ventricle
What is the aetiology of mitral stenosis?
- Rheumatic heart disease
- Congenital MS
- Systemic conditions such as lupus and rheumatoid arthritis
What is the most common cause of mitral stenosis?
Rheumatic heart disease
What is mitral stenosis?
Narrowing of the mitral valve so the orifice is <2cm
What is the pathophysiology of MS?
- Atrioventricular pressure gradient increases
- Left atrium pressure increases
- Pulmonary venous and capillary pressure increase
- Peripheral vascular resistance increases
- Pulmonary arterial pressure increases and pulmonary hypertension develops
- Right heart dilation with tricuspid regurgitation and pulmonary regurgitation
In MS what remains normal?
Left ventricle pressure and systolic function
What determines the severity of MS?
- Trans-valvular pressure gradient
- Trans-valvular flow rate
What affects trans valvular flow rate?
- CO
- HR
When does MS usually become apparent?
With conditions that cause tachycardia
Give examples of conditions which can cause tachycardia.
- Exercise
- Acute illness
- Pregnancy
- Atrial fibrillation
How does MS present?
- Dyspnoea (mild exertional to pulmonary oedema)
- Haemoptysis ( due to rupture of thin walled veins)
- Systemic embolization
- Infective endocarditis
- Chest pain
- Hoarseness
What may be found on examination of someone with MS?
- Mitral facies
- Normal pulse
- Prominent JVP wave
- Tapping apex beat and diastolic thrill
- Right ventricicular heave
- Diastolic murmur
- 3rd HS
What are the investigations for MS?
- ECG (RV hypertrophy)
- Cardiac catheterisation
- CXR (LA enlargement)
- ECHO
- MRI
What is the non-interventional treatment for MS?
- Diuretics and restriction of Na intake
- If in AF, sinus rhythm restoration or ventricular rate control
- Anticoagulation of those in AF
What is the interventional treatment for MS?
- Valvotomy (balloon vs surgery)
- Mitral valve replacement
What is mitral regurgitation?
Mitral valve becomes leaky/incompetent
What is the aetiology of MR?
- Rheumatic heart disease
- Mitral valve prolapse
- Infective endocarditis
- Degenerative
- LV and annular dilatation
What is the most common cause for MR in the developed world?
Mitral valve prolapse
What is mitral valve prolapse?
- Degenerative condition which occurs mostly in men aged 40-50.
- The valve is no longer attached to the chordae tendinae
What is the pathophysiology of MR?
- Effective regurgitant orifice not fixed
- Extremely dependent on preload, afterload and LV contractility
- Annular enlargement lead to increase in regurgitant volume
- LV tries to compensate
How does the LV try to compensate in MR?
- In acute end systolic pressure and end systolic volume decrease. Wall tension also decreases
- In chronic, end diastolic volume increases and end systolic volume returns to normal, eccentric left ventricular hypertrophy develops
How is LA compliance effected in MR?
-A combination of increase and decrease
How is LA compliance decreased?
- Marked pressure rise
- Thickening of atrial myocardium
- Increase in PVR and remodelling of the pulmonary vasculature with PHT
How is LA compliance increased?
- Marked volume enlargement
- Lesser changes in pulmonary vasculature
- Development of AF
How does acute MR present?
Breathlessness due to pulmonary oedema or cardiogenic shock
How does chronic MR present?
- Fatigue
- Exhaustion
- Right heart failure
- Dyspnoea or palpitations due to AF
What would be found on examination of MR?
- Normal pulse (reduced in HF)
- JVP prominent if RH failure present
- Brisk and hyperdynamic apex beat
- RV heave
- Reduced S1 and split S2
- Murmur
What investigations should be carried out for MR?
- ECG
- CXR
- Cardiac catheterisation
- ECHO
What would be seen on MR ECG?
- LA enlargement(p>0.12s, tall)
- RVH (prominent R wave in R precordial leads)
What would be seen on MR CXR?
- Cardiomegaly
- LA enlargement
- Calcification of mitral annulus
What should be looked at on ECHO for MR?
- LV dimensions
- Cause of MR (leafelt dysfunction, chordae, papillary muscles, annular disease)
- Severity of MR and Pap
What is the non-interventional treatment for MR?
- Acute: preload and afterload reduction (sodium nitroprusside, dobutamine, IABP)
- Chronic:watchful waiting
What is the interventional treatment for MR?
- Mitral valve apparatus repair
- Mitral valve replacement
What is the anatomy of the aortic valve?
- Tricuspid valve with 3 cusps
- Located between aorta and left ventricle
What is aortic stenosis?
Narrowing of the aortic valve orifice <1.5-2cm
What is the aetiology of aortic stenosis?
- Degenerative
- Rheumatic
- Bicupsid
What is the pathology of rheumatic aortic stenosis?
- Adhesion
- Fusion of the commissures and retraction
- Stiffening of the free cusp margins
What is the pathology of degenerative aortic stenosis?
- Linked to atherosclerosis
- A slow inflammatory process resulting in thickening and calcification of the cusps from base to free margins
What is the pathophysiology of AS?
- Increased LV systolic pressure
- Severe concentric hypertrophy and LVM
- Increased LVEDP (LA pressure increases)
- PHT
- Increased MVO2
- Myocardial ischaemia
- LV failure
What are the symptoms of AS?
- Long asymptomatic period
- Chest pain
- Syncope/dizziness
- Dyspnoea on exertion
- Heart failure
What would be found on clinical examination of AS?
- Small volume and slow rising pulse
- JVP prominent if RH failure present, low BP
- Vigorous and sustained apex beat
- RV heave
- Normal S1 with less audible ST
- Systolic ejection murmur
What are the investigations for AS?
- ECG
- CXR
- Cardiac catheterisation
- ECHO
What would be seen on AS ECG?
- LVH voltage criteria
- ST/T changes (LV strain
- Taller R waves
What would be seen on AS CXR?
Calcification of AV
What would be seen on AS ECHO?
- Demonstrates the AV cusp mobility
- LV function and hypertrophy
- Doppler haemodynamic assessment of pressure gradient and AVA
Who is medical treatment limited to for AS?
Those who develop heart failure
What is the interventional treatment available for AS?
Aortic valve repair or replacement
What is the aetiology of aortic regurgitation?
Aorta -Dilated aorta (hypertension, Marfans) -Connective tissue disorders Leaflets -Bicuspid aortic valve -Rheumatic heart disease -Endocarditis -Myxomatous degeneration
What is the pathophysiology of AR?
- LV accommodates both SV and RegVol
- Increased LVEDV and LV systolic pressure
- LV hypertrophy and LV dilatation
- Increased MVO2
- Myocardial ischaemia
- LV failure
What are the symptoms of chronic AR?
- Long asymptomatic phase
- Exertional dyspnoea
What are the symptoms of acute AR?
-Poorly tolerated as wall tension cannot adapt
What would be found on clinical examination of AR?
- Large volume and collapsing pulse
- Wide pulse pressure
- Hyperdynamic, displace apex beat
- Early diastolic murmur
What investigations should be carried out for AR?
- ECG
- CXR
- ECHO
What would be seen on ECG of AR?
- ST/T changes (LV strain)
- LAD
What would be seen on CXR of AR?
-Cardiomegaly in chronic AR
What would be seen on ECHO of AR?
- Demonstrates the AV cusp anatomy (thickening, prolapsing, number of cusps, vegetations)
- LV function, dilatation and hypertrophy
- Doppler haemodynamic assessment of regurgitant flow
What is the medical treatment for AR?
-Vasodolator therapy shown to delay the timing for surgical intervention
What is the interventional treatment for AR?
Aortic valve repair or replacement
