Valvular Heart Disease Flashcards
Objectives
- Know common heart valve lesions
- Learn about the patho-physiology of each
- Recognise the symptoms of valve disease and natural progression of the disease
- Learn about the diagnostic investigations
- Learn about the treatment
In valvular heart disease, how does damage to one valve affect others?
If one valve is affected, there’s a high likelihood that others will be as well.
What is mitral stenosis?
Mitral stenosis is a narrowing of the mitral valve opening that blocks (obstructs) blood flow from the left atrium to the left ventricle.
- Mitral stenosis usually results from rheumatic fever.
Aetiology of Mitral stenosis
- Rheumatic heart disease
- Congenital MS
- Systemic conditions: SLE, RA
Pathophysiology of mitral stenosis
- MV orifice <2cm2
- A-V p gradient increases
- LA pressure increases
- Pulmonary venous and capillary pressure increases
- PVR increases
- PaP increases and PHT develops
- RH dilatation with TR and PReg
What occurs to LV pressures and systolic function in mitral stenosis?
They remain normal
Clinical manifestations for mitral stenosis
- Dyspnoea: mild exertional to pulmonary oedema
- Haemoptisis: rupture of thin-walled veins
- Systemic embolisation: LA and LAA enlargement
- IE
- Chest pain
- Hoarseness (compression of the L recurrent laryngeal nerve).
Clinical examination signs of mitral stenosis
- Mitral facies: discolouration of the cheeks and the nose
- Pulse: normal
- JVP: prominent a wave
- Tapping apex beat and diastolic thrill
- RV heave
- Auscultation
Investigation techniques for mitral stenosis
- ECG
- Cardiac catheterisation
- Chest X-ray
Imaging in mitral stenosis
- Echocardiography:
thickening and scarring of the leaflets
Fusion of the commissures - Cardiac magnetic resonance
What is the medical treatment used for mitral stenosis?
- Diuretics and restriction of Na intake
- AF: SR restoration or ventricular rate control
- Anticagulation: all those with AF, debatable in SR
Interventional treatment for mitral stenosis
- Valvotomy (balloon vs surgical)
- MVR (mitral valve replacement)
Aetiology and Pathology of mitral regurgitation
- Rheumatic heart disease
- Mitral valve prolapse (MVP)
- IE
- Degenerative
- Functional MR due to LV and annular dilatation
Pathophysiology of mitral regurgitation
- ERO - not fixed: preload, afterload, LV contractility
- LV compensation:
Acute: ESP and ESV decreases, Wall tension decreases
Chronic: EDV increases and ESV returns to normal, eccentric LVH develops
What occurs due to reduced LA compliance in mitral regurgitation?
- Marked pressure rise
- Thickening of atrial myocardium
- Increase in PVR and remodelling of the pulmonary vasculature with PHT.
What occurs due to increased LA compliance in mitral regurgitation?
- Marked volume enlargement
- Lesser changes in pulmonary vasculature, but develops AF.
Clinical manifestations in mitral regurgitation
- Acute MR (valve perfusion, chordal/pap muscle)
Breathlessness: pulmonary oedema, cardiogenic shock - Chronic MR
Fatigue, exhaustion (low CO), Right heart failure
Dyspnoea or palpitations due to AFib
Is acute mitral regurgitation quite bad?
Yes acute MR is an emergency
Clinical examination signs for mitral regurgitation
- Pulse: normal or reduced in heart failure
- JVP: prominent if RH failure present
- Brisk and hyperdynamic apex beat
- RV heave
- Auscultation: holosystolic, blowing, loud at apex, radiating to the axilla, no relationship between intensity and severity.
What imaging is used for mitral regurgitation?
Echocardiography:
- LV dimensions
- Cause of MR: leaflet dysfunction, chordae, pap mscles, annular disease
- Severity of MR and Pap
- Accurate cardiac volumes
- Volumetric determination of Reg Vol
What medical treatment would be used for Acute MR?
Since preload and afterload reduction may be life-saving
- Sodium nitroprusside, dobutamine, IABP
What medical treatment would be used for Chronic MR?
Lack of evidence that any therapy is beneficial for haemodynamic improvement
- LV function preservation
Interventional treatment for Mitral regurgitation
- Mitral valve apparatus repair
- Mitral valve replacement
Structure and function of the aortic valve
- It is one of the semilunar valves
- It normally has three cusps
- The aortic valve opens, allowing blood to exit the left ventricle into the aorta depending on pressure.
Normal AVA= 3-4cm2
Aortic stenosis aetiology
- Degenerative
- Rheumatic
- Bicuspid
AVA< 1.5-2cm2
Patho-physiology of aortic stenosis
Rheumatic: adhesion, fusion of the commissures and retraction and stiffening of the free cusp margins.
Degenerative: linked to atherosclerosis, a slow inflammatory process resulting in thickening and calcification of the cusps from base to free margins.
Order of pathophysiology of aortic stenosis
Increased LV systolic pressure > Severe concentric hypertrophy and LVM > Increased LVEDP (left atrial pressure increases, PHT) > Increased MVO2 > Myocardial ischaemia > LV failure
Symptoms of Aortic stenosis
- Long asymptomatic phase
- Cardinal symptoms:
- Chest pain (angina)
- Syncope/Dizziness (exertional pre-syncope)
- Breathlessness on exertion
- Heart failure
Clinical examination signs of aortic stenosis
- Pulse: small volume and slowly rising
- JVP: prominent if RH failure present, low BP.
- Vigorous and sustained apex beat
- RV heave
- Auscultation: late peaking, loud at the base, harsh, radiating to the carotids
Laboratory investigations for aortic stenosis
- ECG: LVH voltage criteria, ST/T changes (LV strain)
- Chest X-ray: calcification of AV
- Cardiac catheterisation: Peak LV-peak aortic gradient-obsolete.
Imagine used for aortic stenosis
- Echocardiography
- CMR (cardiovascular magnetic resonance)
Features of Echocardiography in aortic stenosis
- Demonstrates the AV cusp mobility
- LV function and hypertrophy
- Doppler haemodynamic assessment of pressure gradient and AVA
Who gets medical treatment for aortic stenosis and what is the treatment?
- Limited to those who develop heart disease.
- May be treated with digoxin, diuretics, ACE inhibitors, or angiotensin receptor blockers.
Interventional treatment for aortic stenosis
Aortic valve replacement or repair
Aetiology of aortic regurgitation
- Aorta: dilated aorta(Marfans, hypertension), connective tissue disorders
- Leaflets: bicuspid aortic valve, rheumatic heart disease, endocarditis, myxomatous degeneration
Order of pathophysiology of aortic regurgitation
LV accommodates both SV and RegVol > Increased LVEDV and LV systolic pressure > LV hypertrophy and LV dilatation > Increased MVO2 > Myocardial ischaemia > LV failure
Symptoms of chronic aortic regurgitation
- Long asymptomatic phase
- Exertional breathlessness
Symptoms of acute aortic regurgitation
- Poorly tolerated as wall cannot acutely adapt
LV pressure x LV radius/wall thickness
Clinical examination signs of aortic regurgitation
- Pulse: large volume and collapsing (Corrigan sign)
- Wide pulse pressure
- Hyperdynamic, displaced apex beat
- Auscultation: early diastolic, descresendo, soft murmur
Imaging used in aortic regurgitation
- Echocardiography: Demonstrates the AV cusp anatomy (thickening, prolapsing, number of cusps, vegetations)
- LV function, dilatation and hypertrophy
- Doppler haemodynamic assessment of regurgitant flow
- Cardiovascular magnetic resonance (CMR)
Medical treatment used for aortic regurgitation
- Vasodilator therapy shown to delay the timing for surgical intervention.
Interventional treatment used for aortic regurgitation
Aortic valve replacement or repair
