Systolic function and Aortic valve Flashcards
measures of systolic function
fractional shortening nml >30
fractional area change nml >50
ejection fraction >55
SV and CO
Dp/dt
V of circumferential shortening
End systolic elastance
preload recruitable stroke work
strain rate
tissue doppler peak systolic velocity
Fraction indices
all are (Diastolic - systolic) / diastolic
Qp/Qs
SVpa/SVlvot, helps to determine shunt
Inward radial motion of normal , hypokinetic, akinetic, dyskenitic function
normal - greater than 30%
hypokinetic - 10-30 %
Akinetic less than 10%
dyskinetic - paradoxical systolic motion
Dp/Dt
slope of LV pressure rise from 4-36 mmHg, need MR jet, measured at 1 and 3 m/s
Normal is 1610 +/- 290 mmHg/sec (around 1300 min)
velocity of circumferential shortening
FS with ET in denominator
end systolic elastance
Load Independent. Slope of PV loop at end systole points. Steeper slope is better systolic function
preload recruitable stroke work
Stroke work is the area under curve of PV loop. If this is plotted as function of end diastolic volume
Steeper slope is better systolic function
preload adjusted max power
Stroke work/EDV^2 or
stroke work/ EDA^(3/2)
load independent
tissue doppler peak systolic velocity
faster sā is better systolic function, no normal values to be tested on
influenced by tethering and translation
strain rate
Strain is dimensionless, and change in length produced by application of stress
strain rate is strain/time
Translation and angle independent but limited by noise
load independent
Aortic root size
normally less than 4 cm in adult
Basic views of Aortic valve
ME AV SAX, LAX
Deep TG LAX
TG LAX
ME 5 chamber
AI acute vs chronic
acute- stroke work preserved, elevated end diastolic pressure
chronic - compensates by dilating and lower end diastolic pressure, larger stroke volumes. Eventually sarcomeres stretch too far and causes decompensation
Intervene before it becomes too dilated and decreased SV
Severity of AI
Jet height : LVOT diameter
mod 25-64%
Jet area : LVOT area
mod 5-59%
Jet depth
mod tip of AL
VC
greater than 6mm severe
Slope of jet decay
greater than 3 m/s severe
PHT
mod 200-500 ms, affected by diastolic function
Flow reversal in Aorta
3 things determine prognosis in AI.
LV dysfunction
LV dilation
Asc Ao dilation- sinus best predictor (normal 25-31mm)
High risk AI patients
symptomatic
Reduced EF
end systolic diameter indexed >25mm/m2 (81 vs 34% survival at 10 years)
Low risk group Marfan syndrome for AI
Indexed sinus / predicted sinus diameter that is less than 1.3 or less than 5% change annually
When to replace valve
symptomatic or
asymptomatic with severe chronic AR, or chronic AR with root dilation
Types of AI classes
type 1 a- 1 d is normal cusp motion
type 2 - cusp prolapse, common
type 3 - cusp restriction
Aortic stenosis assessment
peak velocity - mod 3-3.9 m/s
mean grad - 30-49 mmHg
max grad - 40-69 mmHg
DVI mod 0.25-0.5 independent of patient size, stroke volume (TVI LVOT/TVI AV) or ( A valve/ A LVOT)
AVA mod 1-1.5 cm2
Indexed AVA mod 0.6-0.85 cm2/m2
If mean gradient is high then you are done
If low, need to see if there is low flow and use cont eq or DVI
Modified gorlin equation
Shows how you can have low gradient but still have aortic stenosis
AVA = CO/ Peak grad