M-mode echocardiography provides high temporal resolution images of cardiac structures along a single ultrasound beam. It was initially used to evaluate motion of the mitral valve, interventricular septum, and aortic and pulmonary valves. Measurements like E-point septal separation are used to estimate left ventricular ejection fraction. Abnormalities detected by M-mode include mitral stenosis, mitral regurgitation, aortic regurgitation, and pericardial effusions. M-mode remains useful for evaluating rapid cardiac motion.

2. DEVIKA SHIJU

3. M-mode
 Also known as the time - motion mode,
developed by Edler.
 The M- mode presentation depicts anatomy
along a single dimension corresponding to the
ultrasound beam creating what has been called
the "ice-pick" view of the heart.
 Initially the method of cardiac ultrasound used
was A (amplitude) mode, which evolved to B
(brightness ) mode and then the M mode was
developed.

6.  In the early years of clinical echocardiography, M-
mode scanning formed the backbone of clinical
echocardiography.
 By positioning the transducer over different
acoustic "windows" of the chest wall, single-
dimensional images of cardiac structures could be
recorded and inferences about structure,
dimensions, and function could be made.

7. Physics
 Ultrasound is emitted from the transducer as a brief
pulse of energy.During the intervals when it is not
releasing the ultrasound waves, it 'listens' for the
incoming reflected signals.
 To perform M-mode examinations, pulse repetition
rates of between 1,000 and 2,000 are used.
 Although the pulse repetition rate is lower for M-
mode, because all the pulses are devoted to a single
raster line, the temporal resolution is actually
much higher for M-mode compared with 2D
echocardiography.

8.  To obtain an M-mode image, a single raster line
from the 2D image is selected and displayed.
 Distance, or depth, is displayed along the vertical
axis and time along the horizontal axis.
 One of the strengths of M-mode
echocardiography is the very high temporal
resolution that it provides.
 This yields a very rapid sampling rates of 1,000 to
2,000 images/s and affords the ability to record
subtle and/or high-frequency motion.

9.  M -mode has an important role in evaluation of
rapid motion of cardiac structures. Since the
sampling rate is very rapid.
 eg.Abnormalities of IVS motion,such as those due
to LBBB,RV volume overload or abnormal RV
filling patterns.
 Subtle abnormalities of MV can be seen using M
mode.These include fine fluttering associated
with AR and B bump caused by elevated LV
diastolic pressure.

10.  M Mode echocardiography interrogates only along a
straight line,it is not a comprehensive anatomic
screening method.
 Another limitation is that the true orientation of the
beam with respect to accurate cardiac anatomy is
often not known if stand- alone transducer is used
Advantage:
 High temporal resolution
 spatial resolution along single line of interrogation is
higher than 2D echocardiography.

12. M MODE : MITRAL VALVE

14.  D point :closed MV at initaiation of diastole.
 E point :peak anterior excursion of AML from midline
with rapid filling of LV in early diastole.
 F point:peak posterior excursion of AML as LV filling
raises intracavity pressure and pressure gradient
between LA and LV declines.This is the end of rapid
filling phase.
 A point:transient increase in LA pressure with Atrial
systole.
 C point :MV closure at onset of systole.

15. B - bump
 A similar example is the B-bump of MV closure.
 This is a particular motion of the MV that occurs
in late diastole as the valve drifts shut with
increasing left ventricular pressure.
 The prolongation of the closing phase of the
mitral valve has been termed the B bump and has
been associated with increased LVEDP (& left
atria).

17. Mitral stenosis
 M-mode echocardiography was one of the early
tools used for the evaluation of rheumatic mitral
valve disease.
 The hallmark of rheumatic heart disease on M-
mode echocardiography was increased
echogenicity of the leaflets with decreased
excursion and reduced seperation of the anterior
& posterior leaflets.
 This was accompanied by a reduced diastolic (E-F)
slope of mitral closure.

19.  Additional features of mitral stenosis noted on
M-mode echocardiography included
"paradoxical" anterior diastolic motion of the
posterior mitral valve leaflet.
 This occured because tethering at the tips
resulted in an obligatory anterior motion of the
posterior leaflet tips that tethered to the larger
anterior leaflet.

21. Mitral valve prolapse : M-mode features
 With M-mode echocardiography, Hammocking
or sagging of the PML or AML atleast 3 mm below
closure point is diagnostic of MVP.

24. Mitral regurgitation : M-mode features
 Indirect evidences - LA enlargement, LV
enlargement.
 Exaggerated septal motion(1cm).

27. Vegetations
Showing vegetation on AML

31. M MODE: AORTIC VALVE

33. Measurements of the LA to aortic ratio

35.  As the aortic jet cascades across AML ,it creates high
frequency fluttering that requires the rapid sampling
rate of M mode for detection.
 AR:
 Diseases that affect aortic root can cause regurgitation by
altering geometry of aortic leaflet coaptation, primarily
through dilation of sinotubular junction.
AR jet arises centrally and vary over full range of severity.
Causes: Endocarditis and Aortic dissection.

36.  AR leads to dilation of LV
 Hyperdynamic IVS motion occurs as a result of LV
volume overload due to unequal filling and SV of
ventricles.
 Which often reveals an exaggeration of normal early
diastolic septal dip and overall increase in amplitude
of septal motion compared with posterior LV wall.

37.  Premature opening of the AV in AR

38. M-mode Aortic regurgitation
 Increased duration between E and A peaks.
 Fluttering of the anterior mitral valve leaflet.

39. Morphology of Bicuspid Aortic Valve

40.  AS:
 AV is thickened with decreased cusp opening
 LV hypertrophy.
 Partial mid systolic closure of AV may be the best way to
differentiate subvalvular from valvular stenosis.
 BICUPID AV
 It can cause a combination of AS And AR .
 Asymmetric closure during diastole.
 (eccentric closure line).

42.  HOCM:
Normal opening of AV ,but early closure occurs in mid
systole at the time of SAM causing LVOT obstruction.
ASH:Hypertrophy of IVS to a greater extend than that of
LVPW.
SAM:During mid systole AML moves anteriorly to coapt
with septum.

43. M MODE :PULMONARY VALVE
 M-mode also provides unique information on the pulmonary
valve.
 In a pulmonary valve M-mode echocardiogram, the small letters
indicate the various motions of a normal pulmonary leaflet.
e point:pv in closed position
f point:posterior excursion of valve apparatus with RV diastolic filling.
a point :additional blood flow to RV after RA contraction result in slight
increase in RVEDP,causing momentary excursuion of valve
b point:ventricular systole result in mild anterior excursion of valve
apparatus.
c point:RV contraction and blood flow through RVOT causes rapid
posterior deflection of the right cusp.
d point:Gradual closure of PV with progression of RV systole.

45. Here, the downward motion labelled "a" corresponds to
atrial contraction and corresponds to the A-wave of
mitral valve doppler inflow.

46.  Large a wave may suggest PS
 Systolic motion of PV is also affected by pulmonary
vascular resistance.
 Mid systolic closure of valve secondary to elevated
pulmonary vascular resistance.
 This appears anterior excursion of right cusp along CD
slope known as flying W sign.

48.  On M-mode echocardiography, pericardial
effusion appears as an echo-free space both
anterior and posterior to the heart. The size of the
echo-free space is directly proportional to the
amount of fluid.

50.  M-mode
echocardiograms
recorded in patients
with pericardial
effusions. A: The
echo-free space
immediately behind
the posterior wall of
the LV consistent
with a small PEF.The
space is larger in
systole than in
diastole. B: The pt
has a larger PEF with
respiratory
variation in right
ventricular size and
septal position.

51. M-mode echocardiograms
recorded in two patients
with cardiomyopathy and
systolic dysfunction. In
each case, note the
increased E-point septal
separation indicative of
reduced EF.The EPSS is (A)
1.2cm and (B) 3.0cm. This
suggests that the EF for the
patient represented in B is
substantially worse than
that in A. The inset in A
demonstrates a classic b-
bump in MV closure.Note
that the smooth
continuation between the
A point and the closure
point(c) is interrupted by
transient reopening of the
mitral valve denoted by
the B-bump, which is
indicative of elevated left

52.  Evaluation of the aortic valve motion also
provides clues to left ventricular performance.
 Normally, the aortic valve has crisp opening and
closing points and as such opens as a "box" when
imaged with M-mode echocardiography.
 Reduced forward flow results in a more gradual
closure during systole so that there is rounding of
aortic valve closure due to reduced forward flow.

54. findings of altered
hemodynamics

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