Valvular Heart Disease Pathophysiology, Presentation and Investigation Flashcards
What are the common heart valve lesions?
Mitral stenosis
Mitral regurgitation
Aortic stenosis
Aortic regurgitation
What are some possible causes of mitral stenosis?
Rheumatic heart disease
Congenital
Systemic e.g. systemic lupus erythematosus
What are some possible causes of mitral regurgitation?
Rheumatic heart disease Infective endocarditis Degenerative Mitral valve prolapse Ventricular and annular dilatation (functional MR)
What are some possible causes of aortic stenosis?
Degenerative
Rheumatic heart disease
Bicuspid aortic valve
What are some possible causes of aortic regurgitation?
Marfan’s
Hypertension
Connective tissue disorders
What is mitral stenosis?
Where mitral valve orifice < 2cm^2
What is the physiological impact of mitral stenosis?
Atrium-ventricle pressure gradient increases
Left atrial pressure increases
Pulmonary venous and capillary pressures increase
Pulse volume recording increases
Pulmonary arterial pressure increases and pulmonary hypertension develops
Right heart dilatation occurs with tricuspid regurgitation
What effect does mitral stenosis have on left ventricular pressures and systolic function?
Left ventricular pressures and systolic function remain normal
What does mitral valve stenosis severity vary with?
Trans-valvular pressure gradient and flow rate
Cardiac output
Heart fate
What are the symptoms of mitral stenosis?
Dyspnoea - ranging from mild exertional to pulmonary oedema
Haemoptysis (due to rupture of thin-walled veins)
Chest pain
Hoarseness (compression of left recurrent laryngeal nerve)
Infective endocarditis
What are the signs of mitral stenosis?
Systemic embolisation - left atrial and left atrial appendage enlargement Mitral facies Prominent a-wave of JVP Tapping apex beat Diastolic thrill Right ventricular heave
What is the effect of mitral stenosis on the pulse?
Pulse is normal
What investigations might be done for mitral stenosis?
ECG Cardiac catheterisation CXR Echocardiography Cardiac MRI
What would be seen on the ECG in mitral stenosis?
P wave > 0.12msec, right ventricular hypertrophy
What would be seen on the CXR in mitral stenosis?
Left atrial enlargement
What would be seen on echocardiography in mitral stenosis?
Thickening and scarring of the leaflets, fusion of the commissures
What are the physiological effects of mitral regurgitation?
Regurgitant volume increases with annular enlargement
Left ventricular compensation occurs
In acute LV compensation, end diastolic pressure and volume decreases and wall tension decreases
In chronic LV compensation, end diastolic pressure increases and end systolic volume returns to normal, and eccentric left ventricular hypertrophy develops
What are the changes in left atrial compliance seen in mitral regurgitation?
Reduced - marked pressure risk, thickening of atrial myocardium, increase in PVR and remodelling of the pulmonary vasculature with PHT
Increased - marked volume enlargement, lesser changes in pulmonary vasculature, but develop in atrial fibrillation
Combination of the two may occur
What does the effective regurgitant orifice depend on?
Preload
Afterload
Left ventricular contractility
What are the symptoms and signs of acute mitral regurgitation?
Pulmonary oedema
Cardiogenic shock
Dyspnoea
(due to valve/chordal/papillary muscle perforation)
What are the symptoms and signs of chronic mitral regurgitation?
Fatigue Exhaustion (due to low CO) Right heart failure Dyspnoea Palpitations due to atrial fibrillation
What might be seen on clinical examination of a patient with mitral regurgitation?
Normal pulse, or reduced in heart failure
Prominent JVP if right heart failure present
Brisk and hyperdynamic apex beat
Right ventricular heave
Auscultation - reduced S1, split S2, early A2, loud P2
Holosytolic murmur - blowing, loud at apex, radiation to axilla, no relationship between intensity and severity
What investigations might be done for mitral regurgitation?
ECG CXR Cardiac catheterisation Echocardiography Cardiac MRI
What might be seen on ECG in mitral regurgitation?
Left atrial enlargement - P > 0.12 msec, tall
RVH - prominent R wave in right precordial leads
What might be seen on CXR in mitral regurgitation?
Cardiomegaly
Left atrial enlargement
Calcification of mitral annulus
What might be seen on echocardiography in mitral regurgitation?
LV dimensions
Leaflet dysfunction
Chordae tendinae, papillary or annular disease
What are the physical effects of rheumatic aortic stenosis?
Adhesion
Fusion of the commissures and retraction and stiffening of the free cusp margins
What are the physical effects of degenerative aortic stenosis?
Slow inflammatory process resulting in thickening and calcification of the cusps from base to free margins
What are the physiological effects of aortic stenosis?
Increased LV systolic pressure Severe concentric hypertrophy and LVM Increased LVEDP Increased MV O2 Myocardial ischaemia LV failure
What are the symptoms and signs of aortic stenosis?
Long asymptomatic phase Chest pain Syncope/dizziness Dyspnoea on exertion Heart failure
What might be seen on clinical examination of a patient with aortic stenosis?
Small volume and slow rising pulse
Prominent JVP if right heart failure present
Vigorous and sustained apex beat
RV heave
Ausculation - normal S1 but less audible A2
Late peaking harsh sounds radiating to the carotids and loud at the base
What investigations might be done for aortic stenosis?
ECG CXR Cardiac catheterisation Echocardiography Cardiac MRI
What might be seen on ECG in aortic stenosis?
LVH voltage criteria
ST/T changes
What might be seen on CXR in aortic stenosis?
Calcification of AV
What can echocardiography demonstrate which is useful in diagnosing aortic stenosis?
AV cusp mobility
LV function and hypertrophy
Doppler haemodynamic assessment of pressure gradient and AVA
What is the aetiology of aortic regurgitation?
Dilated aorta in Marfans/connective tissue disorders
Leaflets
- bicuspid aortic valve
- rheumatic heart disease
- endocarditis
- myxomatous degeneration
What are the physiological effects of aortic regurgitation?
Left ventricle accommodates both SV and regional volume
Increased LVEDV and LV systolic pressure
LV hypertrophy and dilatation
Increased MV O2
Myocardial ischaemia
LV failure
What are the symptoms and signs of chronic aortic regurgitation?
Long asymptomatic phase
Exertional breathlessness
What are the symptoms and signs of acute aortic regurgitation?
Poorly tolerated - wall tension cannot acutely adapt
What might be seen on clinical examination of a patient with aortic regurgitation?
Large volume collapsing pulse
Wide pulse pressure
Hyperdynamic displaced apex beat
Auscultation- normal S1 and S2, early diastolic, soft murmu
What investigations might be done for aortic regurgitation?
ECG CXR Cardiac catheterisation Echocardiography Cardiac MRI
What might be seen on ECG in aortic regurgitation?
ST/T changes
What might be seen on CXR in aortic regurgitation?
Cardiomegaly in chronic AR
What might be demonstrated in echocardiography that could be useful in the diagnosis of aortic regurgitation?
AV cusp anatomy - thickening, prolapsing, number of cusps, any vegetations
LV function, dilatation and hypertrophy
Doppler haemodynamic assessment of regurgitant flow
What are the treatment options for mitral stenosis?
Diuretics and restriction of sodium intake
SR restoration or ventricular rate control for a-fib
Anticoagulation for all patients with a-fib
Valvotomy
MVR
Only treated medically in late/severe stages due to possibility of haemodynamic disturbance
When is intervention indicated in mitral stenosis?
When patients become restricted by their symptoms
What are the treatment options for mitral regurgitation?
Acute
- preload and afterload reduction e.g. sodium nitroprusside, dobutamine
Chronic
- lack of evidence that any therapy is beneficial for haemodynamic improvement
- LV function preservation
Mitral valve apparatus repair or replacement
What are the treatment options for aortic stenosis?
Medical treatment limited to those who develop heart failure
Aortic valve replacement or repair
What are the treatment options for aortic regurgitation?
Vasodilator therapy shown to delay timing for surgical intervention
Aortic valve replacement or repair
