Echo

Question 1

PISA

Answer 1

Area of flow acceleration and convergence proximal to MV as the jet approaches the orifice
Nyquist between 18-40 cm/sec when zoomed in on hemisphere
Record: radius of hemisphere or proximal flow convergence (cm), peak mitral MR vel (cm/sec) and VTI (cm)
Requires elliptical hemisphere and good alignment with a central jet
Flat PISA- underestimate flow rate, peaked PISA- overestimate flow rates

Question 2

Flow rate equation

Answer 2

2πr^2 x Va= ml/sec

Question 3

Effective regurgitant orifice area (EROA) equation

Answer 3

(flow rate ml/sec)/(MRmax cm/sec)= cm^2

Question 4

Regurgitant volume equation

Answer 4

EROA cm^2 x MR vti cm= cc

Question 5

Lagrangian Strain

Answer 5

Change of myocardial fiber length during stress at end systole compared to its original length at end diastole

Question 6

Strain

Answer 6

dimensionless quantity of myocardial deformation. Usually expressed as %. Measures magnitude of myocardial fiber contraction and relaxation

Question 7

Hooke’s Law

Answer 7

Passive wall stress-contractile force= elasticity x deformation

Question 8

Speckle tracking echo (STE)

Answer 8

computes deformation from standard 2D grayscale images. Measures primarily myocardial displacement (TDI assesses tissue velocity). Detects spatial movement during heart cycle and can calculate lagrangian strain

Question 9

4 methods of semi quantitative assessment of MR

Answer 9

Regurgitant jet area, PV flow, angiography, spectral doppler

Question 10

4 Methods of quantitative assessment of MR

Answer 10

Doppler, PISA, Vena contracta, 3D echo

Question 11

Limitations of PISA

Answer 11

Assumes regurgitant orifice is circular and flat
Assumes flow convergence is hemispheric
Requires single MR jet
Does not represent entire systole
Small measurement errors are magnified

Question 12

Ways to measure AR

Answer 12

Diastolic MV flutter, CF doppler- Jet height to LVOT area, proximal flow convergence, vena contracta

Question 13

dP/dV

Answer 13

myocardial stiffness

Question 14

dV/dP

Answer 14

Compliance

Question 15

L wave

Answer 15

Mid diastolic flow (between E and A wave)
Bradycardia in healthy cats or severe impaired relaxation

Question 16

E’ determinants

Answer 16

LV relaxation, recoil, lengthening load (measure of early diastolic filling volume)
also HR, age, body size, non uniformity of LV relaxation
technically pre-load dependent but not with severe impairment- “relatively preload independent”

Question 17

A’ determinants

Answer 17

LA contractility, LA relaxation, LVEDP