Diastolic Function

Question 1

Diastolic function — simplified algorithm

Answer 1

1. TDI e’ velocity
   •e’ ≥ 10 cm/s —> grade 0 - Normal
   •e’ < 10 cm/s —> step 2
2. E/e’ velocity
   •E/e’ ≤ 8 —> grade 1 - impaired relaxation
   •E/e’ 9-12 —> grade 2 - pseudonormal
   •E/e’ ≥ 13 —> grade 3 - restrictive

Question 2

4 phases of diastole

Answer 2

1. Isovolumetric relaxation — rapid decrease in LV pressure until below LAP then MV opens
2. Early filling (E) — caused by gradient between LAP and LV pressure with brisk filling and increased LV volume accounting for 80%
3. Diastasis — not much LV filling occurs due to lack of a pressure gradient
4. Late filling (A) — atrial contraction occurs establishing a gradient between LA and LV for last 20% contribution of LV filling

Question 3

Impaired Relaxation pattern

Answer 3

• prolonged IVRT — ‘suck’ impaired so takes a longer time to generate a negative pressure to open the MV
• peak E velocity is low because active relaxation is less vigorous
• E wave and DT prolonged because it takes longer for peak E velocity to occur and for the chambers to equilibrate
• no diastasis phase because the atrium contracts before the end of early filling
• ’A’ wave contracts when it is more full therefore contributes more to diastolic filling than normal

Question 4

Restrictive pattern — decreased LV compliance

Answer 4

• IVRT decreased — decreased compliance causes an increased LAP which pops the MV open with rapid early filling and a high peak E velocity
• period of diastasis
• DT decreased — pressures equilibrate rapidly
• small ‘A’ wave with increased E/A because the atria contracts against a stiff non compliant ventricle

Question 5

Pseudonormal pattern

Answer 5

•unable to determine by transmitral flow velocities alone
•occurs in setting of impaired relaxation and decreased compliance because the decreased compliance causes elevated LAP which compensates for the impaired relaxation to a perfect point to make it look normal
•differentiate from a truly normal pattern by looking at PWD pulmonary venous inflow:
S < D because when MV closed the LAP is increased which decreases forward flow through the PV…
When MV opens the pressure gradient rapidly improves so the D wave is very large [D large if E large] …
Large A wave in size and duration (PVF A wave > TMF A wave) — won’t see increased PVF A wave size if LA failure but will have prolonged duration compared to TMF A wave

Question 6

Limitations of transmitral and pulmonary venous inflow profiles

Answer 6

•Loading conditions — NTG, valsalva, anesthesia, PPV
preload:
Increased LAP —> increases E wave and E/A (shifts pattern to the right)
Decreased LAP —> reverts to pseudonormalization pattern (shifts pattern to left — if it does NOT revert then is considered end stage diastolic dysfunction)
•Mitral regurgitation — increases LAP
•Mitral stenosis — increases LAP and will see reversal of PVF A wave
•Arrhythmias — atrium contracting against a closed valve in CHB produces a very large atrial reversal
•Heart rate — elevated HR decreases diastasis time and late filling contributes more than early filling so E/A decreases

Question 7

Color M-mode flow propagation velocities (Vp)

Answer 7

•ME4C view with narrow CFD and M-mode scan line from MV annulus to LV apex
•measure the slope of the first aliasing velocity of the early filling profile [E wave]
Steeper the slope = better the diastolic function
•measured 4 cm into the LV cavity
•load dependent !!! (Preload) — increases with preload in ALL patients
•normal = slope > 45-50 cm/s
•E/Vp ≥ 2.5 predicts PCWP ≥ 15 … only if LVEF is reduced
•less reproducible — subjective

Question 8

Tissue Doppler

Answer 8

Mitral annular velocities — septal or lateral
•measure how fast it moves upwards during diastole
•relatively load independent in diastolic dysfunction — the sicker the patient the better the measurement
•load dependent in normal patients**
•low velocity, high amplitude signals
•systolic (s’), early (e’), late (a’)

Velocities:
•e’ < 8 cm/s = bad [diastolic dysfunction but impaired compliance too?]
•e’ 8 - 10 = indeterminate [look at other stuff]
•e’ ≥ 10 = good [normal diastolic function]
•e’/a’ < 1 = bad (independent of doppler angle)

• e’ does not pseudonormalize
• Average over 3+ cardiac cycles
• Angle dependent (keep angle < 20º)
• E/e’ is unreliable in normal patients
• Measure e’ first and if abnormal then measure the E/e’