Valvular Heart Disease Flashcards
What is stenosis?
A narrowing
What is the definition of mitral stenosis?
a mitral valve orifice that is less than 2cm
What effect does mitral stenosis have?
Atrial>Ventricular pressure/LA pressure/ pulmonary venous/capillary pressures/PVR/PaP increase, pulmonary hypertension develops as does right heart dilatation causing tricuspid regurgitation
What can cause the stenosis to become more severe?
Anything that increases CO and HR e.g. exercise, acute illness, pregnancy and atrial fibrillation
What are the clinical manifestations of mitral stenosis?
Dyspnoea (pulmonary oedema), haemoptysis (rupture of thin-walled veins), systemic embolization (LA and LAA enlargement), IE, chest pain and hoarseness (compression of the L recurrent laryngeal nerve)
What would the findings be on examining someone with mitral stenosis?
Mitral facies, normal pulse, JVP - prominent a wave, tapping apex beat, diastolic thrill, RV heave and a murmur between S2 and S1 on auscultation
What investigations might be done to diagnose mitral stenosis?
ECG, CX-Ray, echocardiography and cardiac MR
What is the treatment for mitral stenosis?
Diuretics and restriction of sodium intake, AF: SR restoration/ventricular rate control, anticoagulation for all those with AF (debatable in SR), valvotomy (balloon vs surgical) and MVR
What are the causes or mitral regurgitation?
Rheumatic heart disease, mitral valve prolapse, IE, degenerative and functional MR due to LV and annular dilatation
What is ERO?
Effective regurgitant orifice
What factors affect the ERO?
Preload, afterload and contractility
What happens when the left ventricle tries to compensate for the regurgitation?
EDV increases and ESV returns to normal causing eccentric LVH
What happens when LA compliance is reduced?
There is a marked pressure rise, thickening of the atrial myocardium, increase in PVR and remodelling of the pulmonary vasculature with PHT
What happens when LA compliance is increased?
There is marked volume enlargement and lesser changes in pulmonary vasculature but they develop atrial fibrillation
What are the clinical manifestations of mitral regurgitation?
Acute MR (valve perforation, chordal/pap muscle) - breathlessness, pulmonary oedema and cardiogenick shock. Chronic MR - fatigue, exhaustion (low CO), right heart failure and dyspnoea/palpitations caused by AF
What would the findings be on examining someone with mitral regurgitation?
Pulse may be normal or reduced (heart failure), JVP will be prominent if RH failure is present, Apex beat will be brisk and hyperdynamic, RV heave and on auscultation there will be a reduced S1, a split S2, an early A2 and a loud P2 which will radiate to the axilla
What investigations would be done to diagnose mitral regurgitation?
ECG (LA enlargement and RVH), CX-Ray (cardiomegaly, LA enlargement and calcification of the mitral annulus) and echocardiography (LV dimensions, cause of the MR, severity of the MR and Pap)
What is the treatment for mitral regurgitation?
Acute MR: preload and afterload reduction may be life saving (sodium nitroprusside, dobutamine and IABP).
Chronic MR: lack of evidence that any therapy is beneficial for haemodynamic improvement and LV function preservation.
Interventional Treatment: Mitral valve apparatus repair and mitral valve replacement
What are the three main causes of aortic stenosis?
Degenerative, rheumatic and bicuspid
How does rheumatic disease cause aortic stenosis?
Adhesion, fusion of the commissures and retraction and stiffening of the free cusp margins
How does degeneration cause aortic stenosis?
It is linked to atherosclerosis - a slow inflammatory process resulting in the thickening and calcification of the cusps from base to free margins
What effect does aortic stenosis have?
It increases LV systolic pressure which causes severe concentric hypertrophy, LVM, increased LV EDP and increased MVO2 which leads to myocardial ischaemia and LV failure
What are the cardinal symptoms of aortic stenosis?
Angina, syncope/dizziness, breathlessness on exertion and heart failure
What would the findings be on examining those with aortic stenosis?
Pulse - small volume and slowly rising
JVP - prominent if RH failure present, low bp
Vigorous and sustained apex beat
RV Heave
Auscultation: Murmur peaks in mid systole, loud at the base and radiates to the carotids
What investigations are used to diagnose aortic stenosis?
ECG: LVH voltage criteria, ST/T changes (LV strain)
CX-Ray: calcification of AV
Echocardiogram: demonstrates the AV cusp mobility, LV function and LV hypertrophy
CMR
What treatments are used to treat aortic stenosis
Treatments are limited to those who have heart failure.
Aortic valve replacement/repair
What are the causes of aortic regurgitation?
Dilated aorta (Marfans, hypertension), connective tissue disorders, bicuspid aortic valve, rheumatic heart disease, endocarditis and myxomatous degeneration
What effect does aortic regurgitation have on the heart?
The LV accommodates the SV and RegVol which leads to an increase in LV EDV and LV systolic pressure. This in turn causes LVH and LV dilatation which leads to increased MVO2, myocardial ischaemia and LV failure
What are the symptoms of chronic aortic regurgitation?
There is a long asymptomatic phase followed by exertional breathlessness
What are the symptoms of an acute aortic regurgitation?
Acute AR is poorly tolerated as wall tension cannot acutely adapt
What would the findings be on examining someone with aortic regurgitation?
Pulse - large volume and collapsing (Corrigan sign)
Wide pulse pressure
Hyperdynamic, displaced apex beat
Auuscultation: Normal S1 and S2 with an early diastolic decrescendo/soft murmur
What are the investigations done to diagnose aortic regurgitation?
ECG: ST/T changes (LV strain) and LAD
CX-Ray: cardiomegaly in chronic AR
Echocardiogram - demonstrates the AV cusp (thickening, prolapsing, no. of cusps and vegetations) and LV dilatation/function/hypertrophy
CMR
What is the treatment for aortic regurgitation?
Vasodilator therapy - shown to delay the timing for surgical intervention
Interventional treatment: aortic valve repair/replacement
