Module 3 : Diastolic Function Flashcards
definition of diastole
- chambers relax and fill with blood under low pressure
- interval from AV closure to MV closure
definition of relaxation
- includes IVRT and early phase ventricular filling (IVRT E wave)
definition of compliance
- change in volume / change in pressure (Dv/Dp)
- inverse to stiffness
definition of stiffness
- change in pressure / change in volume (Dp/Dv)
- stiffness inverse to compliance
what two pressures are included in filling pressures
- LV EDP
- mean LA pressure
what is LVEDP
- left ventricle end diastolic pressure
- reflects ventricular pressure after filling is complete
what is mean LA pressure
- average pressure during the filling person in the left atrium
what are the 4 phases of diastole
- IVRT
- early phase
- diastasis
- late phase
what is IVRT
- isovolumic relaxation time
- no change in ventricular volume but pressure is ventricle is falling
what is early phase of diastole
- rapid filling of the LV
- caused by suction
what is diastasis
- pressures equalize between LV and LA
- small amount of blood may flow
what is late phase
- atria contract and push the rest through
- atrial kick
- contributes to 20-30% of normal filling
what three things is IVRT influenced by
- conduction abnormalities or conduction mechanics
- loading conditions (preload LAP)
- age
normal IVRT
50-100ms
what is the deceleration time
- LA and LV pressure gradient begins to fall leading to a slow down of blood entering the LV
4 things that influence rapid filling phase
- rate of LV relaxation
- elastic recoil of ventricle
- chamber compliance
- LAP
how much of total volume does early filling contribute
70-80%
normal length of early filling
150-200ms
what determines the length of diastasis
- HR
- slow = long diastasis
- fast = short or absent diastasis
what phase of diastole might be absent with afib
- atrial contraction
what two things are included in LV filling properties
- LV compliance/stiffness
- myocardial relaxation
compliant ventricles and pressure
- able to increase its volume without increasing its pressure significantly
stiff ventricles and pressure
- disproportionate increase in pressure for a relatively small increase in volume
LV mass 2D changes with DD
- Increase age, body weight, blood pressure increases LV mass
- first walls become thicker than dilates
- LV mass will increase with either increase wall thickness or with increase in chamber dimension
LA volume 2D changes with DD
- heart becomes less compliant filling pressures increase
- increased LAEDP and LAP will dilate the LA
- LA is only 2-3mm thick and dilates easy
- > 34ml/m^2 abnormal
4 causes of DD
- primary myocardial disease
- secondary hypertrophy
- coronary artery disease
- extrinsic factors
3 examples of primary myocardial disease
- dilated CMO (cardiomyopathy) (NUMBER ONE)
- infiltrative myocardial disease
- hypertrophic CMO
3 examples fo secondary hypertrophy
- HTN (hypertension)
- aortic stenosis
- severe mitral regurgitation
2 examples of CAD
- ischemia
- infarct
2 examples of extrinsic factors
- pericardial tamponade
- pericardial constriction
7 factors effecting all diastolic measurements
- HR (IVRT shortens, E/A fuse)
- rhythm (AF/PVC)
- preload (artificially increases E wave height)
- LV systolic function (abnormal contraction = abs relaxation)
- respiration
- age
- PR interval
grade 1 DD
- impaired relaxation
- mild diastolic dysfunction
grade 2 DD
- pseudo-normal
- moderate DD
grade 3 DD
- restrictive filling
- severe DD
4 parameters for grading DD
- MV inflow (E/A ratio)
- averaged E/e prime ratio
- left atrial volume index
- TR jet velocity (RVSP)
** 2/3 criteria must be positive to determine grade 2 or 3 DD
normal filling
- LV fills at low pressure because the myocardium is compliant
normal E/A ratio
0.8-2
normal DT
150-200ms
normal MV E wave
- 6-1.3m/s
- reverses near 6th decade of life
definition of DD
- delayed or slowed myocardial relaxation with normal filling pressures
- prolongs iVRT and DT
2 factors affecting filling
- chamber compliance
- extrinsic factors
three tissue doppler waves
- e’ = lengthening of ventricle during early filling
- a’ = atrial contraction
- s’ = systolic contraction (ventricular shortening)
normal medial wall e’
> 7cm/s
normal lateral wall e’
> 10cm/s
normal E/e’ ratio
less than 8
- 8-12
mild DD / impaired relaxation
- reduced E/A ratio (<0.8)
- reduced E velocity
- prolonged DT (>200ms)
- reduced TDI (IVS < 7cm/s, lat <10cm/s)
- E/e prime < 14 (not increased)
- TR velocity jet < 2.8 (normal)
symptoms of mild DD
- mild shortness of breath on exertion SOBOE
TR jet with DD
- in absence of significant pulmonary or right heart disease the TR jet is accurate reflection of left heart filling pressure
- with DD LV, LA, PV, lungs, PA, RV pressure all increase leading to increase TR jet
grade 2 / pseudonormal DD
- imparted relaxation + moderate reduction in LV compliance which results in increased LAP
- MV inflow pattern returns to fairly normal profile due to increase LAP
grade 2 DD MV inflow characteristics
- E/A ratio (0.8-2) looks normal
- DT (150-200) looks normal
- IVRT (50-100) looks normal
- E/e prime 10-14 (abnormal)
- MV inflow A wave duration shortens as LAP increases
symptoms grade 2 DD
- SOB at lower levels of activity compared to grade 1 DD
how to unmask pseudo normal
- VALSALVA
- hold valsalva while pulsing MV
- reduces venous return to Rt heart then left Heart
- reduces LA pressure
- if grade 2 then should changes to grade 1
- e wave will reduce >50% if positive
mid-diastolic flow pseudo normal
- sometimes the LV la pressure gradient is maintained well into diastasis
- this results in flow across the MV during diastasis
what is the wave seen during diastasis in pseudonormal
- L wave
- commonly seen along the LVH at lower heart rates
- what would you see at higher HR
+ L would fuse with E
grade 3 DD/ severe DD
- reduced LV compliance and increased filling pressure leads to tall E wave and short deceleration time LAP ++
symptoms of grade 3 DD
- dyspnea with minimal exertion
- reduced exercise tolerance
- pedal or abdominal edema
grade 3 DD MV inflow characteristics
- increased E velocity
- increased E/A ratio >/= 2.0
- short DT < 150-160-ms
- low e’ < 5cm/s
- increased E/e prime ratio >/= 14 indicates High LAP or filling pressure
when do pulmonary veins fill the LA during
- ventricular systole
- early diastole
- diastasis
when is the flow reversed in the pulmonary veins
- atrial systole
what three things happen with the PV a wave and MV a wave with DD
- PV atrial reversal wave increases velocity
- PV atrial reversal wave increases duration
- MV a wave decreases duration
PVa - MVa normal
< 20ms
PVa - MVa mild DD
< 20ms
PVa - MVa mod DD
> /= 30ms
PVa - MVa sev DD
> /= 30ms
treatment for diastolic dysfunction
- besides treating underlying cause of DD EXERCISE is only direct treatment of DD
3 key differences between RV and LV diastolic dysfunction
- RV inflow velocities vary with respiration
- RV inflow velocities are lower
+ TV area is larger than MV leads to lower filling velocites - RV diastolic FILling time is longer
+ the TV opens before and closes after the MV
3 stages of RV dysfunction
- impaired relaxation
- pseudonormal TV inflow
- restrictive filling
impaired relaxation RV DD criteria
- E/A <0.8
pseudonormal TV INflow RV DD criteria
- E/A 0.8-2.1
- E/e’ > 6 (or HV diastolic flow predominance)
restrictive filing RV DD criteria
- E/A > 2.1
- DT < 120ms
