Week 3 AI Flashcards
When in the cardiac cycle does AI occur? vs when does AS occur?
AI - AoV leaks in IVRT, diastole, IVCT (whenever it is closed - a longer time than AS)
AS - in ventricular ejection
Etiology of AI?
4 things that cause AI
*1. Aortic root dilation - leaflets pulled apart
- Congenital: bicuspid, Marfans, Ehlers-Danlos
- AS, Antherosclerosis, infection, trauma
*2. Cusp abnormalities - cusps don’t close properly
- bicuspid, calcific, rheumatic, infective endocarditis
- Aortic root distortion - Aortitis is inflammation that causes distortion
- inflammatory or infective (bacterial) - Loss of Ao cusp (commissural) support
- VSDs near Ao, Ao dissection, trauma
Ao dilation versus aneurysm? defn
Dilation - big, but not an aneurysm
Aneurysm - 1.5 x bigger than normal (F: 48, M: 52 mm)
Usually we just write “Aortic Dilation”
Acute AI - what happens?
Sudden incr in AI
Incr in blood in LV and incr LV press
Incr in LA press
Incr in lung press
*emergency - can’t breath
Chronic AI, mild - what happens?
Slow incr in AI
concentric LVH (and LV dilation)
Incr in SV (Frank Starling) to pump out extra blood
Therefore, LV press remains normal
*patients may have no symptoms
Chronic, AI, severe (long standing) - what happens?
LV dilation
Incr in AI
Severe LV dilation / eccentric hypertrophy
Therefore,
- Incr LV mass - incr oxygen demand and decr supply - Angina
- Decr EF bc sarcomeres stretched - systolic failure
- heart reaches max size (pericardium) and filling press rise - diastolic failure
Signs and symptoms of acute AI?
Sudden severe SOB
chest pain
tachycardia
murmor
rapidly developing heart failure
signs and symptoms of chronic severe AI?
Decr blood flow to body - SOBOE, fatigue
Incr SV - HT, feeling of forceful heartbeat, high PP
Decr end diastolic press in Ao - decr coronary perfusion
Murmor
AI murmor (vs AS murmor)
AI - Austin flint murmor (last longer - IVRT, diastole, IVCT)
AS - SEM (only during ejection)
Treatment for AI
- monitor with echos: LV size and function, severity of AI and changes, Asc Ao
- If patient has HT or dilation of Ao: meds to decr afterload (beta blockers)
- operate before LV dilation
*EF less than 50% = surgery to replace valve
Is mild AI normal?
No, mild AI is not normal (vs MR and TR - mild is common)
Role of echo in AI
- Determine etiology: AoV pathology or Ao Root dilation?
- Assess LV size and systolic function: 2D measurements (LV mass index, EF), concentric or eccentric LVH?
- Measure Ao and LVOT diam
- Estimate severity of regurg:
- Visual assessment
- PHT
- Flow reversal in Desc Ao
- AI jet width and vena contracta
- PISA
- Estimate severity of regurg:
- Visual assessment?
Colour
in PLAX look at width of jet in LVOT
in SAX look at location of AI
Go off axis to get max regurg?
Colour gain settings?
- Estimate severity of regurg:
- PHT?
PHT = Pressure Half time = the time it takes for PG to drop by half (ms)
5ch CW through AoV
Measure the slope - the steeper the slope means the faster the LV/Ao PG drops and the more severe the AI and the shorter the PHT
bc in AI, both blood from LA and Ao flows into LV in diastole
- Estimate severity of regurg:
- Flow reversal in Desc Ao
- SC Abd Ao - PW
- look for flow reversal below the baseline - SSN Ao - PW
- look for flow reversal above the baseline
- Estimate severity of regurg:
- AI jet width and vena contracta
PLAX - LVOT zoom with colour
Freeze
AI jet width - measure jet width (divide by LVOT width to get %)
Vena contracta - measure narrowest part of the jet when blood is moving through valve
PISA
PISA = Proximal Isovelocity Surface Area
EROA = Effective Regurgitant Orfice Area
PISA = EROA = size of remaining hole when valve is closed
Ap 5 ch - zoom on AoV
Colour - raise baseline to ~30 cm/s
Freeze - scroll to largest PISA radius and measure it (from valve to end of aliasing)
Do CW
trace waveform to get Vmax (and other info)
Machine Calculates EROA
EROA = (2πr^2 * Vn)/Vmax
r is PISA radius
Vn is Colour Nyquist limit (from scale)
Vmax is max jet velocity (from CW)
Categories for when estimating the severity of AI
Trivial
Mild
Mild-mod
Mod
Mod-severe
Severe
What are the 2 times you move the colour baseline from center?
AI - raise baseline for PISA
MR - lower baseline
*to rem: move baseline in same direction as regurg flow in 4 ch or 5 ch
