Tissue Doppler

Question 1

Tissue Doppler Imaging

Answer 1

• Mitral / Tricuspid annular velocities
• high amplitude, low velocity signals (low pass filter on)
• systolic (s’) , early (e’) , late (a’)
• angle dependent (keep < 20º)
• average ≥ 3 cardiac cycles

Question 2

Diastolic Function

Answer 2

• e’ < 8 cm/s = bad
• lateral e’ > septal e’
- exception: constrictive pericarditis (lateral < septal) annular reversus 
• e’ > 10 cm/s = good
• a’ < 10 cm/s = good
• e’ / a’ < 1 = bad
• s’ > 8 = good
• s’ < 5 = bad

Question 3

TDI : detection of ischemia

Answer 3

• s’ , e’ , e’/a’ decrease
• TDI changes occur faster than reduction of systolic excursion & wall motion changes
• post systolic shortening
• isovolumic contraction velocity decreases
• prolongation of the Q-to-peak-s’ time interval
• ECG-Q-to-e’ onset > ECG-Q-to-TMF-E onset

Question 4

TDI limitations

Answer 4

• mitral annular disease / tethering
• time intervals require regular rhythm & stable HR
• regional
• normal patients —> preload dependent
• angle dependent

Question 5

Tamponade vs Constrictive Pericarditis

Answer 5

• Transmitral Inflow

• RICM : e’ < 8 cm/s
• CP : e’ > 10 cm/s ; lateral e’ < septal e’

Question 6

TDI for diastology

Answer 6

• e’ > 10 cm/s —> done.
• e’ < 8 - 10 —> look at other stuff ….
• E/e’ > 13 —> elevated LAP

Question 7

TDI for MPI

Answer 7

• measures both systolic and diastolic function
• lower number = better
•MPI = (IVCT + IVRT) / ET
- normal = 0.4
- elevated MPI = abnormal systolic & diastolic function

Question 8

Right Heart

Answer 8

• RV s’ < 10 cm/s = low in young healthy people
• IVA = 1.4 +/- 0.5 m/s^2 (wide confidence levels = not very reliable)
• MPI = (IVCT + IVRT) / ET
- (TR jet duration - ET) / ET
- relatively independent of HR, preload, and afterload
- measures both systolic and diastolic function
- > 0.5 predictive of HD instability and mortality after valve surgery
•Strain Rate = (V2 - V1) / x
- not used often perioperative but useful in detecting early onset of ischemia prior to detection of WMA