Aortic stenosis Flashcards
definition?
Obstruction of blood flow through the aortic valve due to pathological narrowing.
rf?
• Age>60
• Congenital bicuspid aortic valve
• Rheumatic heart disease
CKD
ddx?
• Aortic sclerosis-less intense murmur and S2 normal split-no sig pressure gradient
• IHD-ECG shows abnormal thickening and Q waves
Hypertrophic cardiomyopathy-murmur increases when standing and squatting and had grip softens it-seen on echo
Aetiology?
• Bicuspid aortic valves
Calcific aortic stenosis
CP?
• RF's • Dyspnoea • Chest pain • Syncope • Ejection systolic murmur • Small BP/low pulse pressure • Systolic thrill over aorta • Harsh crescendo/decrescendo late systolic ejection murmur-radiates to carotids in 2nd right ICS • S2 diminished and single • Early systolic ejection click • Carotid parvus et tardus-carotid upstroke is delayed and diminished • Hand grip decreases intensity; standing from squatting decreases intensity S4 at apex
pathophysiology?
- Usually 3-4 cm2
- Aortic valve doesn’t fully open-<1cm2
- Mech stress overtime-damages endothelial cells around valves-fibrosis and calcification-stiff
- Bicuspid-more risk of fibrosis and calc-stress less equally distributed
- Chronic rheumatic fever-repeated inflammation and repair-fibrosis-commissural fusion of valves
- Stiff-as LV contracts-high pressure-ejection click as snaps open
- Louder in systole and quieter as less blood flowing through/lower pressure as ejection occurs
- LV-higher pressures in contraction-concentric LV hypertrophy to increase contractility
- Less blood to body-risk of heart failure/organ failure
- Symptoms in exercise when increased demand
- Microangiopathic haemolytic anaemia-high blood pressure damages RBC’s -schistocytes-haemoglobinuria
Investigations first line?
- CVS exam-See CP for findings
- ECG-LV hypertrophy due to pressure overload and absent Q waves and can have co-findings of AV block
- Transthoracic Echo/Doppler-high sensitivity and specificity
- Elevated aortic pressure gradient
- Measurement of valve area and LVEF
investigation second line?
- Cardiac MRI-shows stenotic aortic valve
- Cardiac catheterisation-high sensitivity and specificity elevated aortic pressure gradient
- ECG stress testing-if asymptomatic-ST changes, BP or arrhythmias
- Dobutamine stress echo-pseudostenosis and contractile reserve
management unstable?
Balloon valvuloplasty to temporarily relieve stenosis before surgery or transcatheter aortic valve replacement
management stable first line?
- Surgical aortic valve replacement-Risk Assessment tools
- Mechanical/bioprosthetic valves inserted
- LT infective endocarditis AB prophylaxis
- LT anticoagulation-vit K antagonist if mech valves used
management stable second line?
- TAVR-
- During TAVR, a new valve is mounted on a stent and deployed through a catheter, entering the heart either via the femoral artery or through the cardiac apex after a minimally invasive thoracotomy. The transaxillary and the transaortic routes may also be used. Advantages include the avoidance of cardiopulmonary bypass and median sternotomy.
- LT infective endocarditis AB prophyalxis
- LT anticoagulation-vit K antagonist if mech valves used
management high risk?
• Same as above
• Consider risk factors for surgery
Surgery if contractile reserve and low flow and low gradient
management non-surgery?
First line: • TVAR • LT AB and anticoagulation Second line: • Medical therapy to improve co-morbidities and balloon valvuloplasty
management asymptomatic?
• Follow up and consider prophylactic valve replacement
prognosis ?
- Better with surgery
- Surgery is very effective-depends on risk-but EF and heart failure symptoms improve
- TAVR-better quality of life -5 yr mortality 72% compared to 94%
