M-mode questions

What is M-mode

the first echo technique to provide quantitative data, displayed in time

M-mode's strength

very high temporal resolution

obtaining M-mode

a single raster/cursor line in 2D is displayed perpendicular to the structure

measuring structures in M-mode

leading edge to leading edge

3 measurements in M-mode of the AoV

1. LA end systole dimension

2. AoR dimension at end diastole

3. ACS - Aortic valve systolic separation

3 measurements in M-mode of the MV

1. MV E-F

2. MV EXC

3. EPSS

7 measurements in M-mode of LV

1.RVIDd

2.IVSd

3.LVIDd

4.LVPWd

5.IVSs

6.LVIDs

7.LVPWs

Color m-mode shows -

the motion of flow and demonstrates the propagation velocity of blood flow

Color M-mode used as

a parameter of diastolic function

diastolic flutter of AMVL

aortic insufficiency

B-notch

elevated LV end-diastolic pressures (HFpEF)

sampling of M-mode

high rate of sampling, optimal images of rapidly moving structures like the IVS

M-mode findings that indicate LBBB

paradoxical septal motion due to delayed contraction of IVS

M-mode findings that indicate RV overload

a D-shaped, flattened IVS

a septal bounce in M-mode indicates

constrictive pericarditis - ventricles must "share space"

Cardiac tamponade causes

early diastolic collapse of the RVFW

mid-systolic closure of the aortic valve

valvular obstruction in hypertrophic cardiomyopathy

SAM

systolic anterior motion of MV leaflets, reduced opening of MV leaflets in diastole

causes of SAM

obstruction of LVOT during systole due to hypertrophic cardiomyopathy

_____ is missing in SAM

A-point

MVP findings in M-mode

a "droopy" C-point due to the valve bulging into LV during closure

large distance between the septum and the E-point of the mitral valve (abnormal EPSS)

Dilated cardiomyopathy

disadvantages of M-mode

- limited spatial orientation

- overestimation of LV dimensions in the low parasternal window

- inaccuracy of FS and EF in apical infarction leading to false estimation of LV global performance

Horizontal axis

time

Vertical axis

distance or depth