valvular heart disease Flashcards
(30 cards)
left untreated, what can valvular heart disease lead to?
Left uncorrected, valvular heart disease often leads to irreversible ventricular dysfunction and/or pulmonary hypertension.
what are the classic symptoms of aortic stenosis?
angina
heart failure
syncope
(the classic triad)
also
decrease in exercise tolerance
dyspnoea on exertion
what are the causes of aortic stenosis?
- age related (senile calcification, most common)
- congenital (bicuspid valve, williams syndrome)
- CKD
- previous rheumatic fever
where is aortic stenosis best heard on auscultation?
2nd intercostal space right side
best described as ejection systolic, radiating to carotid/neck
how is AS assessed initially?
by echocardiography
this allows quantification of the severity of stenosis and assessment of the rest of the heart
doppler echo can estimate the gradient across valves
what are the indications for surgery in AS?
Symptoms caused by AS (regardless of severity). If symptomatic, prognosis is poor without surgery.
Asymptomatic severe AS with left ventricular systolic dysfunction.
Asymptomatic severe AS with abnormal exercise test (symptoms, drop in BP ST changes).
Asymptomatic severe AS at the time of other cardiac surgery (e.g. CABG)
what should transcather aortic valve implantation be considered in AS?
In older patients, especially those with significant co-morbidities, transcatheter aortic valve implantation (TAVI) should be considered. This is implanted via the femoral artery.
usually the recommended treatment.
how does aortic regurgitation lead to heart failure?
Patients with chronic aortic regurgitation (AR) may remain asymptomatic for many years despite significant regurgitation.
The increased volume load on the left ventricle leads to progressive LV dilatation and ultimately heart failure.
what are the acute and chronic causes of aortic regurgitation?
Chronic
- Congenital
- CT disorders (Marfan’s syndrome, Ehlers–Danlos), - rheumatic fever
- RA, SLE
Acute
- infective endocarditis
- ascending aortic dissection
- chest trauma
what are the symptoms of aortic regurg?
- exertion dyspnoea
- reduced exercise tolerance
- orthopnoea (SOB when lying flat)
- palpitations
- angina
- syncope
where is an aortic regurgitation murmur best heard?
The murmur is best heard at the left sternal edge and is an early diastolic blowing murmur that is associated with a collapsing pulse and other synonyms such as De Musset’s sign (head bobbing).
murmur is also heard best in expiration with patient sat forward
how can an ACEi be used to treat aortic regurgitation?
Afterload reduction (with ACEI) can slow the rate of left ventricular dilatation and is now standard therapy in patients with severe AR and LV dilatation.
how are patients with aortic regurgitation assessed?
echocardiography is diagnostic. This allows quantification of the severity of the regurgitation and assessment of the rest of the heart.
CXR will show cardiomegaly.
what are the indications for surgery in AR?
Symptomatic severe AR
Asymptomatic severe AR with evidence of early LV systolic dysfunction (EF < 50% or LV end-systolic diameter > 5 cm or LV end-diastolic diameter > 7·0 cm)
Asymptomatic AR of any severity with aortic root dilatation > 5·5 cm (or > 4·5 cm in Marfan syndrome or bicuspid aortic valve).
what signs are seen in aortic regurgitation?
collapsing pule
De muse’s sign = head nods with each heart beat
Quincke’s sign = capillary pulsation in nail beds
Duroziez’s sign = in the groin, a finger compressing the femoral artery 2cm proximal to the stethoscope gives a systolic murmur; if 2cm distal, it gives a diastolic murmur as blood flows backwards
Traube’s sign = ‘pistol shot’ sound over femoral arteries
how is AR managed?
aim is to reduce systolic hypertension
ACE-i are helpful
echo every 6-12 months
Aim to replace valve before significant LV dysfunction
what are the causes of mitral/tricuspid valve regurgitation?
Functional (RV dilatation; eg due to pulmonary hypertension induced by LV failure or PE)
rheumatic fever
infective endocarditis
congenital (eg Ebstein’s anomaly (downward displacement of the tricuspid valve)
Drugs
what are the symptoms of mitral valve regurgitation?
Fatigue
hepatic pain on exertion (due to hepatic congestion)
ascites
oedema
symptoms of the causative condition.
what are the signs of of MV regurgitation?
pansystolic murmur, heard best at lower sternal edge in inspiration
pulsatile hepatomegaly
jaundice
ascites.
how is MV regurgitation assesed?
MR is best assessed by echocardiography. It is essential to assess LV function and size together with the severity of the jet of blood coming through the valve.
how is MV regurgitation treated?
The surgical options in MR include mitral valve replacement or mitral valve repair. Surgical intervention is generally indicated in severe MR for:
- Symptomatic patients (with symptoms due to the MR).
- Asymptomatic patients with mild-moderate LV dysfunction (EF 30 - 60% and LVESD 4·5 - 5·5 cm).
Medical therapy of MR is restricted largely to the use of diuretics. In patients with functional or ischaemic MR (resulting from dilated or ischaemic cardiomyopathy), ACEI are beneficial.
If LV systolic dysfunction is present, treatment with drugs such as ACEI and β-blockers such as Bisoprolol or Carvedilol and CRT have all been shown to reduce the severity of MR.
what cardiac conditions can predispose people to infective endocarditis?
mitral valve prolapse
presence of prosthetic material (e.g. valves and patches, but not coronary stents)
rheumatic heart disease,
degenerative and bicuspid aortic valve disease,
many forms of congenital heart disease
IE may also involve previously normal heart valves and may be associated with infection due to an intravascular device.
what does a fever and a new murmur suggest?
Fever + new murmur = endocarditis until proven otherwise.
Any fever lasting >1wk in those known to be at risk must prompt blood cultures.
what are the commonest causative organisms in IE?
viridans group of streptococci and Staphylococcus aureus
In IV drug users Staphylococcus aureus is commonest,
Enterococcal endocarditis may be a pointer to disease of the GU or lower GI tract.
Around 2 - 10% of cases are caused by fungi (mainly Candida or Aspergillus), particularly in patients with immunosuppression, IV drug use, cardiac surgery, prolonged exposure to antimicrobial drugs and IV feeding.