Valvular diseases Flashcards
Normal aortic valve area?
3-4 cm2
What is aortic stenosis
obstruction of blood flow across the aortic valve due to pathological narrowing.
RFs for aortic stenosis
- Hypercholesterolaemia
- Hypertension
- Smoking
- Diabetes
- Rheumatic heart disease
How many valves does the normal aortic valve have?
Tricuspid
Types of congenital aortic stenosis?
Congenital aortic stenosis
Congenital bicuspid valve
Types of aortic stenosis?
Supravalvular
Subvalvular
Valvular
How does congenital aortic stenosis work?
Happen in unicuspid, bicuspid, tricuspid valve
Associated with aortic coarctation, dissection or aneurysm
Symptoms shown in 30s to 50s
When do symptoms of aortic stenosis occur?
Symptoms occur when valve area is 1/4th of normal.
What does aortic valve look like normally?
Closed - Mercedez logo
open - hole
If theres fusion of the tricuspid valve what can you get?
BAV - bicuspid aortic valve
BAV symptoms:
0.5-2% of general population
Up to 10% of first degree relatives will have BAV
Associated aortopathy and coarctation
Aortic valve normally
The aortic valve is normally made up of three leaflets: the left, the right, and the posterior leaflet. It opens during systole to allow blood to be ejected to the body. During diastole, it closes to allow the heart to fill with blood and get ready for another systole.
What is the pathophysiology of aortic stenosis?
Smaller valve - dont open as easily - LV contracts creates high pressure pushing on valve until it snaps open - “ejection click”
Blood flows through narrower opening - creates murmur - louder as blood flows pas opening and quierer as it subsides - crescendo decrescendo
LV generates higher pressure - undergoes concenctric hypertrophy - still enough blood may not leave heart - lead to HF
What is the presentation of aortic stenosis?
Syncope: (exertional) 15%
Angina: (increased myocardial oxygen demand; demand/supply mismatch) 35%
Dyspnoea: on exertion due to heart failure (systolic and diastolic) 50%
Sudden death <2%
What are the physical signs of aortic stenosis?
Slow rising carotid pulse (pulsus tardus) & decreased pulse amplitude (pulsus parvus)
Ejection click
Heart sounds- soft or absent second heart sound, S4 gallop due to LVH - As valve becomes narrower second heart sound gets softer and softer and eventually goes away - murmur
Ejection systolic murmur- crescendo-decrescendo character.
“Loudness” does NOT tell you anything about severity
Symptoms of aortic stenosis
- Fatigue
- Shortness of breath
- Angina
- Dizziness
- Fainting
Natural history of aortic stenosis:
Mild AS to Severe AS:
8% in 10 years
22% in 22 years
38% in 25 years
The onset of symptoms is an indication of poor prognosis if left untreated.
What is the prognosis of AS?
Angina + AS: 50% survive for 5 years.
Syncope + AS: 50% survive for 3 years,
HF + AS mean survival is <2 years.
Risk of Sudden Cardiac Death in asymptomatic or minimally symptomatic patients is rare (<2%).
How do we investigate aortic stenosis?
Echocardiography
Two measurements obtained are:
Left ventricular size and function: LVH, Dilation, and EF
Doppler derived gradient and valve area (AVA)
Severity of AS:
mild: AVA >1.5cm2 Velocity 2.6-3m/s
moderate: 1-1.5cm2 3-4m/s
Severe: <1cm2 >4m/s
What is the management for AS?
General:
Fastidious dental hygiene / care
Consider IE prophylaxis in dental procedures
Medical - limited role since AS is a mechanical problem. Vasodilators are relatively contraindicated in severe AS
Aortic Valve Replacement:
Surgical
TAVI – Transcatheter Aortic Valve Implantation
What is TAVI?
TAVI – Transcatheter Aortic Valve Implantation
Pass balloon into damaged aortic valve – pass new valve through the aorta to sit above the old valve to put a new valve in – not an operation – is a PCI
When do we intervene with AS?
Any SYMPTOMATIC patient with severe AS (includes symptoms with exercise)
Any patient with decreasing EF
Any patient undergoing CABG with moderate or severe AS
Consider intervention if adverse features on exercise testing in asymptomatic patients with severe AS