Module 16 : Introduction to Diastolic Function Flashcards
diastole- definition
- phase of heart cycle where the chambers relax and fill with blood
- interval from AV closure to MV closure
relaxation - definition
- relaxation of the ventricle including IVRT and early phase ventricular filling
compliance - definition
- change in volume / change in pressure
- in the LV during diastole
- compliance is inverse to stiffness
- if compliant then not stiff
stiffness - definition
- change in pressure/ change in volum e
- in LV during diastole
- inverse to compliance
- if stiff not compliant
filling pressure - definition
- includes LV EDP and mean LA pressure
LVEDP- definition
- left ventricular end diastolic pressure
- reflects left ventricular pressure after filling is complete
+ after MV doppler A wave
mean LAP - definition
- average pressure during LV filling period only during diastole
- left atria pressure
diastolic function - definition
- ability of ventricle to all to an adequate volume at end diastole to ensure that there is enough forward volume during systole
+ bad diastolic function leads to congestive hear failure
normla diastolic function
- means that LV can fill to an adequate volume with low filling pressures during rest or exercise
diastolic dysfunction
- the LV can fill to ensure a normal forward volume but only when the filling pressure increases to abnormal levels
- # 1 symptom of diastolic dysfunction is shortness of breath
normal LV filling doppler qualities
- tall E wave
- smaller A wave
- steep deceleration time
- short IVRT
normal E wave value
- 6 - 1.3 m/s
- age dependant
- reverses in 6th decade of life
normal deceleration time value
160 - 220 ms
normal A wave value
no normal
- less than E wave
normal E/A ratio
> /= 0.8 - 2
how to measure IVRT
- find clear A4C view aligned to MV inflow
- place cursor so pulsed wave sample volume is straddling the red inflow path and blue outflow path
- press PW
- optimise signal
- measure between aortic outflow (closing click) and MV valve opening
Normal IVRT value
50-100 ms
LV end diastolic filling pressure
- pressure in the LV just after LA contraction
- should be pretty high
mean LA pressure
- pressure in LA averaged over the LV filling period mLAP
- diastole
normal filling pressure
- both LV and LA normally fill under low pressure
< 12 mmHg
elevated filling pressure
> 15 mmHg
diastolic dysfunction vs increased filling pressure
not the same thing
elevated filling pressure - definition
- consequence of diastolic dysfunction (diastolic dysfunction leads to increased filling pressures)
- when lv loses its ability to real and becomes more stiff then the pressure rise to maintain normal forward flow in systole
normal filing
- LV fills at low pressure because myocardium is compliant
- if LV was stiff the filling pressure would rise above normal forcing the LA pressure to increase to maintain a pressure gradient to sustain forward flow
abnormal diastolic filling - factors affecting filling
1) chamber compliance
2) hypertrophy / infiltrative disease
3) extrinsic factors
+ pericardial stiffness
4) LV muscle remodelling
+ post MI (scarring)
5) normal change with age
+ fibrotic change in the LV increases LV stiffness with age
MV doppler wave - abnormal filling
- reduced E wave
- prolonged IVRT
- tall A wave
- no gap between E and A
- increased DT
factors affecting early diastolic filling
- volume (preload)
- hyper/hypovolemia
- excessive mitral regurge
+ increases volume of blood movxngpast MV
+ starlings law
factors affecting late diastolic filling
- cardiac rhythm \+ organized P waves not in Afib and flutter - atrial contractile function - increased LVEDP - HR - ventricular diastolic function
impaired LV filling - physiology
- as we get older LV muscle becomes less compliant during diastole
- LV does not expand as quickly therefore the LV/LA pressure gradient is reduced which reduced E wave peak velocity
- leads to lower velocity E wave and relatively higher velocity A wave
ways that LV expands in diastole
- radially
- circumferentially
- LONGITUDINALLY
- torsion
tissue doppler of MV annulus
- velocity of expansion or contraction can be measured using pulsed wave doppler
- these velocities are less dependant of preload than MV inflow doppler
TDI/TVI
- same thing
- as ventricles fill during diastole the annulus moves way for the apex and moves outward circumfrenetially
- velocity of lengthening is measured in longitudinal plane
- measures the speed of tissue movement not blood movement t
- should resemble a mirror image of MV velocity profile on a lower scale
- one upward wave and two downward waves
abnomal TDI of MV
- small e’ (e prime)
waves of TDI
s prime (s') e prime (e') a prime (a')
s prime
- systolic motion of the mortal annulus towards the probe in systole
e prime
- early diastolic motion of the MV annulus toward the probe in systole
a prime
- late diastolic motion of the MV annulus in the late diastole away from the probe
normal TDI - medial e prime
> /= 8 cm/s
normal TDI - lateral e prime
> /= 10 cm/s
TDI - age related
- the younger and more athletic you are the higher the velocity tissue doppler will be
+ increases rate of expansion enhancing starlings - more efficient heart
e/ e’ ration
- evelocity divided by e’ velocity
- need sam units
- the smaller the ratio the better
- larger ratio means increased filling pressure
normal e/e’ ration
< 8
abnormal e/e’ with elevated filling pressure
> 15
pulmonary venous flow
- pulmonary veins fill the LA during
\+ ventricular systole
\+ early diastole
\+ diastasis
- flow is reversed in the pulmonary veins during
\+ atrial systole or late diastolewhat pulmonary vein do we usually pulse
right upper pulmonary vein RUPV
pulmonary vein waves
S wave (systolic) d wave (diastolic) a wave reversal (atrial kick)
S wave
- systolic wave
- normally greater than d wave velocity
- divided into s1 and s2 waves
- occasionally discernable
d wave
- diastolic wave
- normally smaller than S wave
a wave reversal
- cause by atrial kick
- blood temporarily flows back into the PV form LA die to lack of valve
diastolic dysfunction and RVSP
- as LV diastolic function remains abnormal for long period of time the increased filling pressure leads to increased pressure in the lungs due to backward transmission of pressure
- the increased pressure in the lungs can be measured via RSVP
- higher levels of diastolic dysfunction are associates with
+ TR jet velocity > 2.8
+ RVSP > 40mmHg
LV wall and LA size with diastolic dysfunction
- hypertension is one of the biggest causes of diastolic dysfunction
- hypertension is a high afterload condition leading to increased LV muscle mass and thickness
- a thicker LV muscle is stiffer and less compliant muscle
- this leads to increased filling pressure
- as filling pressure increases the LA size does too
- LA muscle is thin and will dilate under these condition
