The Basics Flashcards
What are the three primary causes of AS (from most to least common)?
- Calcific (most common)
- Rheumatic
- Congenital (least common)
What are the types of bicuspid aortic valve?
Type 0: 0 raphe, true BAV
Type 1: 1 raphe (most commonly raphe between RCC and LCC)
Type 2: 2 raphe (functionally unicuspid)
What is a raphe?
Seam/fibrous ridge between two cusps (also known as a false commissure)
Which is the most common type of BAV?
Type 1 (one raphe) with raphe between the right and left coronary cusps
Prevalence of AS in patients < 50 years old?
AS patients < 50 years old are likely to have a bicuspid AV
Prevalence of AS in patients > 70 years old?
AS patients > 70 years old are likely to have a tricuspid AV
Progression: How does AV sclerosis become calcific AS?
Three stages:
- Endothelial Damage
- Fibrosis
- Calcification
Initiating factors of AS
- Mechanical stress
- Bicuspid aortic valve
- Genetic factors
Risk factors for AS
- Older age
- Male
- Hypertension
- Diabetes
- Smoking
- Metabolic syndrome
Haemodynamic Consequences of AS
- Adaptation of the left ventricle
- Left atrium
- Cardiac output
- Perfusion
- End-stage
Haemodynamic Consequences of AS: Adaptation of the Left Ventricle
- Increased LV systolic pressure leading to concentric hypertrophy
- Decreased LV compliance
- Increased filling pressures
Haemodynamic Consequences of AS: Left Atrium
- LA dilatation (as a result of decreased LV compliance and increased LV filling pressures)
- Increase in LAP
- Can lead to development of AF
Haemodynamic Consequences of AS: Cardiac Output
- Initially normal CO (due to compensatory mechanisms)
2. CO declines as disease progresses
Haemodynamic Consequences of AS: Perfusion
Decreased CO leads to decrease in 1) myocardial and 2) cerebral perfusion
Haemodynamic Consequences of AS: End-Stage
- Reduction in LV contractile function
- Pulmonary hypertension
- RV dysfunction
What are the ‘classic’ symptoms of AS?
- Angina
- Syncope
- Heart failure
What causes angina?
Due to decreased myocardial perfusion and ischemia
What causes syncope?
Due to decreased cerebral perfusion
What causes heart failure?
Due to the inability of the heart to supply sufficient blood flow to meet the needs of the body
What are the early but non-specific symptoms of AS?
- Exertional dyspnoea (decreased exercise tolerance)
- Exertional dizziness (pre-syncope or syncope)
- Exertional angina
What are the management strategies for AS?
Management strategies consider stages, diagnosis, medical therapy and interventions
What categories are the stages of AS defined by?
Each stage is defined by:
- Valve anatomy
- Valve haemodynamics
- Haemodynamic consequences
- Symptoms
What are the interventional options for patients with severe AS?
SAVR - surgical AV replacement
TAVR - trans catheter (trans femoral) AV replacement
What are other causes of LV Outflow Obstruction?
Subvalvular AS and supravalvular AS
What is subvalvular AS?
Obstruction below AV (in LVOT)
Can be fixed or dynamic obstruction
Fixed obstruction: discrete fibrous membrane, fibromuscular ridge, fibromuscular tunnel (with septal hypertrophy and thickened amvl)
Dynamic obstruction: HOCM with ASH and SAM
What is supravalvular AS?
Obstruction above AV (distal - on aortic side)
Morphological types: hourglass deformity (most common), fibrous membrane, diffuse hypoplasia ascending aorta
Most often seen in William syndrome
