Cardiology: Valvular Heart Disease: AS & AR Flashcards
Which is the most common valve lesion in the UK? [1]
Aortic stenosis
What is the most common cause of symptomatic AS in children? [1]
unicuspid aortic valve
Describe the three causes of AS [3]
State when they might occur in life [2]
-
Calcific (degenerative)
Affects patients later in life (>65).
Atherosclerosis plays a role in calcification -
Bicuspid valve (congenital)
Stenosis tends to appear at a younger age (< 65). - Rheumatic heart disease
State 4 risk factors for aortic stenosis [4]
- Hypercholesterolaemia
- Hypertension
- Smoking
- Diabetes.
Desribe the pathophysiology of AS
A pressure gradient develops across the valve
Initially, this leads to systolic dysfunction, the heart can not pump out a normal proportion of its end-diastolic volume and causes increased resistance to ejection and increases the systolic pressure gradient.
Compensatory mechanisms result in left ventricular (concentric) hypertrophy - hence, a sustained apex.
This then causes diastolic dysfunction by reducing ventricular filling during diastole
This reduces the compliance of the left ventricle and reduces overall myocardial contractility.
This causes left heart failure
ALSO: the back-pressure from the left ventricle also increases pulmonary artery pressure and can lead to pulmonary hypertension. This eventually progresses to right heart failure.
Describe the effect of AS on coronary arteries [2]
The hypertrophied area has a higher oxygen demand due to fewer capillaries per muscle mass and the larger LV may also compress coronary arteries
The lower stroke volume also causes reduced coronary filling time
Describe the symptoms of AS
Patients with aortic stenosis (AS) may be asymptomatic for a prolonged period of 10-20 years.
-
Exertional dysopnea
Most common complaint -
Exertional angina
Increased o2 demand due to more LV mass and decreased perfusion pressure gradient due to elevated LV end diastolic pressure -
Exertional syncope or presyncope
Due to exercise induced vasodilation and inability to increase CO - Atrial fibrillation
- Epistaxis or bruising
Classical triad of ‘SAD’ is often described.
Syncope; Angina; Dysopnea
Which clotting disease can AS lead to? [1]
Explain your answer [1]
Turbulent flow across the stenotic aortic valve can lead to an acquired von Willebrand deficiency
High shear forces inducing structural changes in the shape of the protein leading to clotting abnormalities.
Describe the signs of AS [4]
Murmur:
* Loud mid-to-late peaking systolic ejection murmur
* Radiates to the carotids and becomes more prominent with sitting forward and in expiration
* Murmur becomes softer the more severe the stenosis
* Murmur radiates to carotids
Sustained apex
Slow rising pulse
Narrow pulse pressure
Soft S2
S4 - caused by the atria contracting against stiff, hypertrophied ventricles.
What ECG changes would you expect in AS? [1]
Left ventricular hypertrophy:
- deep S-waves in V1 and V2
- tall R-waves in V5 and V6).
How can you tell from a murmur in AS if it is mild-moderate c.f severe murmur? [2]
Early peaking is more consistent with mild or moderate AS and late peaking is consistent with severe AS
Murmur becomes softer the more severe the stenosis
What GI symptom might AS patients present with? [1]
gastrointestinal bleeding due to angiodysplasia
- from acquired VWD
How do you determine if an asymptomatic patient has AS? [1]
Perform a Exercise stress testing (EST)
What is a multi-slice CT (MSCT) test for AS? [1]
Used to assess extent of calcification to determine calcium score for severity of AS and may be used to detect CAD in patients who are not eligible for EST
When is dobutamine stress echo indicated in AS patients? [1]
By what mmHg does AS gr
Dobutamine stress echocardiogram:
- useful for patients who have low-gradient AS
- patients may be symptomatic but have seemingly low pressures due to a low ejection fraction
- gradient will increase > 40 mmHg after administration of low dose dobutamine
Describe the work conducted prior to a surgical aortic valve replacement {SAVR) or transcatheter aortic valve implantation (TAVI) [3]
-
Coronary angiogram:
to ID CAD and concomitant coronary revascularization if possible -
Trans-oesophageal echocardiogram (TOE):
assess for endocarditis and mitral valve abnormalities as well as monitoring the TAVI procedure -
MSCT:
assess the anatomy and dimensions of the aortic root, shape of the aortic valve annulus and the number of aortic valve cusps
What is the definitive treatment for AS? [2]
The definitive treatment for AS is surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI).
How do you classify AS as being severe? [3]
Severe AS classified as:
- aortic jet velocity ≥4 m/s (direct measurement of the highest antegrade systolic velocity signal across the aortic valve)
- mean trans-valvular pressure gradient ≥ 40 mmHg
- aortic valve area ≤1 cm2.
What indicates surgery for AS? [3]
If symptomatic
If asymptomatic but have:
- LVEF < 50%
- Undergoing other cardiac surgery
- low surgical risk factors
Which treatment option is used for palliative measures / not suitable for surgery / young children with congenital AS? [1]
Percutaneous balloon valvotomy
When is conservative management indicated in AS patients? [1]
Conservative management is indicated for patients with mild AS who are asymptomatic and have no risk factors.
What is Heyde’ syndrome? [1]
Triad of
- AS
- Recurrent bleeding due to angiodysplasia causing anaemia
- Acquired coagulopathy - VWDS
Explain why angiodysplasia in the intestine may occur for patients with AS? [2]
Von Willebrand multimers get sheared across the narrowed aortic valve as they pass through it with higher velocity.
This prevents them from mediating platelet adhesion at sites of angiodysplasia in the intestine.
What is the difference between long term management in those who recieve a mechnical valve vs a bioprosthetic valve when treating AS? [2]
Which suits younger patients more? [1[
Mechanical valve
- require long-term anticoagulation,
- long lifespan reducing the need for a second operation.
- Suited to younger patients.
Bioprosthetic valve
- no need for long-term anticoagulation
- limited life span (around 10 years) and a repeat operation is more likely.
- Suited to older patients.
State the different aetiologies of AR [6]
Can be split into:
aortic leaflet disease:
* rheumatic infection
* infective endocarditis
* congenital & degenerative disease
aortic root disease:
* aortic dissection
* CT diseases
* aortitis
Pulsation of uvula is a sign of AR. What is the name for this sign?
Duroziez’s
Quincke’s
de Musset’s
Traube’s
Müller’s
A patient presents with head nodding to each heart beat. What is this a sign of?
What is the name for this sign? [1]
Duroziez’s
Quincke’s
de Musset’s
Traube’s
Müller’s
Sign of AR
Duroziez’s
Quincke’s
de Musset’s
Traube’s
Müller’s
What is the name for the sign of pulsating nail beds? [1]
Duroziez’s
Quincke’s
de Musset’s
Traube’s
Müller’s
Which is characterised by the following?
Mitral stenosis
Mitral regurgitation
Aortic stenosis
Aortic regurgitation
Mitral regurgitation
Which is characterised by the following?
Mitral stenosis
Mitral regurgitation
Aortic stenosis
Aortic regurgitation
AS
Which is characterised by the following?
Mitral stenosis
Mitral regurgitation
Aortic stenosis
Aortic regurgitation
MS
Which is characterised by the following?
Mitral stenosis
Mitral regurgitation
Aortic stenosis
Aortic regurgitation
AR
What is an austin flint murmur? [1]
Early diastolic murmur heard in AR; the blood flows out of of atrial valve on onto mitral valve; heard on apex beat
Why are VSDs associated with aortic regurgitation? [1]
poorly supported right coronary cusp resulting in cusp prolapse
