This document discusses M-mode echocardiography, including its physics, applications, and findings. M-mode provides high temporal resolution to evaluate cardiac structure movement and timing. It can be used to assess valves, walls, intervals, and morphology. Examples are given of M-mode findings in various cardiac pathologies at the mitral, aortic, pulmonary, and tricuspid valves as well as the left ventricle. Measurements like fractional shortening and ejection fraction are also reviewed.

1. Dr. Amit Kumar
Senior Resident, Department of Cardiology
R.N.T Medical College
Udaipur , India

2.  For many years, this type of examination was only
available echocardiographic technique. They used to
form backbone of clinical echocardiography.
 Today also M-mode importance couldn’t be
underestimated even in presence of 2D ,3D, real time
3D, or doppler echocardiography.

3. M-Mode Physics
 The transducer emits an ultrasound beam, which
reflects at each anatomic interface.
 The reflected wavefronts can be represented as dots
(B- mode) or spikes (A-mode). Brightness of dot or
magnitude of spike vary with the amplitude of the
reflected wave.
 If the B-mode scan is swept from left to right with
time, an M-mode image is produced

5. M-Mode Physics….
 M-mode has got better temporal resolution and
thus subtle abnormalities in motion and timing is
better appreciated. For eg. systolic anterior motion of
mitral valve in HCM & RV diastolic collapse in
tamponade.
 Because of its high sampling frequency( upto 1000
pulses per second), M-mode has excellent axial
resolution and is useful in identifying the relative
location of structures and measuring range of motion.

6.  M-mode echocardiography is use to evaluate the
morphology of structures ; movement and velocity
of cardiac valves and walls; and timing of cardiac
events.

7. M-mode Evaluation
 Amplitude
 Velocity
 Time intervals
 Morphology

8. Amplitude = Y2 –Y1
Y1
Y2
Amplitude Measurement
Distance
Time

9. Time interval = T2 – T1
T2T1
Time Measurement
Distance
Time

10. dy = Y2 –Y1
Y1
Y2
Slope Measurement
T1 T2
dt = T2 – T1
Slope = dy/dt = velocity

13. M-mode at the Mitral Valve
 The mitral valve has 2 leaflets – anterior
and posterior.

15. Mitral stenosis: M-mode
features
 Decrease EF slope.
 Paradoxical anterior diastolic motion of PML.
 Seperation between leaflets is decreased.
 Thickening of leaflets.
 Early diastolic dip of IVS.
 Reduced mitral valve leaflet excursion( D-E excursion)
 Earlier pliability for BMV used to be decided on basis of D-
E amplitude. A MV with D-E amplitude of 20mm or more
is usually considered pliable.

16. Mitral Stenosis

17. Mitral regurgitation: m-mode
features
 Indirect evidences- LA enlargement, LV enlargement
 Exaggerated septal motion (1cm)
 LAE with systolic expansion of the posterior left atrial
wall.

20. Mitral valve prolapse : m-
mode features
 Thick redundant mitral valve leaflets.
 Mid to late systolic sagging back of the anterior,
posterior or both MV leaflet >2mm from C-D point of
MV.
 Holosystolic sagging back of the anterior, posterior, or
both MV leaflet >3mm from the C-D point of MV.

22. Flail mitral leaflet : m-mode
features
 Coarse diastolic fluttering of mitral leaflets.
 Flail mitral leaflet may appear within LA

25. Infective endocarditis: m-
mode features
 Valve leaflet appear thickened, “smudged”, “shaggy”.
 Vegetation on a valve leaflet usually doesn’t restrict
valve motion.

27. Mitral Valve Endocarditis

28. LA myxoma: m-mode
features
 Blunted E point of the mitral valve.
 Decrease E-F slope.
 Heavy band of echoes behind the anterior mitral
leaflet in diastole.
 Echo free space at anterior mitral leaflet at onset of
diastole prior to dense echoes from tumor

30. Premature closure of Mitral
valve: m-mode features
 When C-point of the mitral valve occurs before the
onset of the QRS complex.

32. Fluttering of AML in aortic
regurgitation

33. “B” bump due to elevated EDP
B-bump or notch

34. Hypertrophic Cardiomyopathy
Systolic anterior motion of
mitral valve s/o dynamic LVOT
obstruction

37. M-mode at the Aortic Valve
 The aortic valve has 3 cusps – right coronary,
left coronary and non-coronary cusps.
 The cusps imaged in the PLAX view are the
right coronary and the non-coronary cusps.
 Leaflet may show fine systolic fluttering in
healthy individuals.

38. M-mode at the Aortic Valve
Coronary
cusp
Non-coronary cusp
Anterior aortic root
Posterior aortic root
Left Atrium

40. M-mode at the Aortic Valve
LA dimension
Cusp Separation (1.5-2.5cms in adult)
Aortic root

41. M-mode at the Aortic Valve
LA dimension
Measurements are made
from leading edge to
leading edge.

42. Aortic stenosis: m-mode
features
 Thickening valve leaflets.
 Decreased excursion of valve leaflet.
 Absence of systolic flutter of aortic valve leaflet.

43. Critical Aortic Stenosis

44. M-mode at the Aortic Valve
Bicuspid Valve
Eccentric closure
line
Seen when there is a
Bicuspid aortic
valve

45. Aortic regurgitation: m-mode
features
 Diastolic fluttering of AML.
 Diastolic fluttering of aortic valve.
 Premature closure of mitral valve.
 Premature opening of aortic valve.
 Dilated LV.

46. Fluttering of AML in aortic
regurgitation

47. Premature opening of Aortic
valve in AR

48. Diastolic fluttering of aortic
valve in AR

49. coarse fluttering of aortic
valve cusp- SUBAORTIC
MEMBRANE

50. Early closure of AV due to Severe LV dysfun
M-mode in a pt with LV dysfunction-
showing rounded closure of
AV,indicating decrease forward flow
at end of systole

51. Systolic notching of AV in
HCM

53. a- downward motion, concides with A-wave of MV; b- represents
onset of ventricular systole; c- max downward position ; d- closure
begins; e- closure is completed

54.  In adults it is unusual to record more than posterior
leaflet of the pulmonary valve.
 In children or in pt with unusually large pulmonary
arteries, one may also record anterior leaflet.
 In reality one can rarely record the entire excursion of
the pulmonar valve throughout cardiac cycle in adults.

55. M-mode at Pulmonary valve

56. Pulmonary stenosis m-mode feature-
increase depth of pulmonary valve “a”
wave (increased a-dip)

57. Pulmonary HTN with “Flying W sign”
Pulmonary hypertension m-mode
feature- loss of A-dip of pulmonary
valve

59. M-mode at tricuspid valve

62. M-mode at Left Ventricle
RVWT

63. M-mode at Left Ventricle
RVIDd

64. M-mode at Left Ventricle
IVSd

65. M-mode at Left Ventricle
LVIDd

66. M-mode at Left Ventricle
LVPWd

67. M-mode at Left Ventricle
IVS excursion

68. M-mode at Left Ventricle
IVSs

69. M-mode at Left Ventricle
LVIDs

70. M-mode at Left Ventricle
LVPWs

71. M-mode at Left Ventricle
LVPW excursion

72. • FS
• EF
• LV mass
M-mode LV Calculation

73. M-mode LV Calculation
FS = LVIDd – LVIDs
LVIDd

74. M-mode LV Calculation
EF = LVIDd3 – LVIDs3
LVIDd3

75. M-mode LV Calculation
LV Mass = 1.04 {(LVIDd + IVSd + LVPWd)3 – (LVIDd)3} x 0.8 + 0.6g

76. LV M-mode parameters
range
 Ventricular end-diastolic dimension- 37 to 56mm
 Ventricular end-systolic dimension- 26 to 36mm
 LV diastolic IVS thickness- 7to 11mm
 IVS excursion – 6 to 11mm
 IVS % thickening- 27 to 70%
 LV posterior diastolic wall thickness- 7 to 11mm
 LVPW excursion- 9 to 14mm
 LVPW % thickening- 25 to 80%
 %FS- 28-41%
 EF- 48-78%

77. LV parameters….
 Stroke volume- 75 to 100cc
 Cardiac output- 4 to 8L/min
 Cardiac index- 2.4 to 4.2L/min/m2
 LV mass- male< 294gm; female<198gm
 Mitral valve EF slope- 50 to 150mm/sec
 DE Excursion- 15 to 25 mm
 Mitral valve E-point septal seperation- <7mm

78. Increase LVW thickness

79. Ischemia

80. Ischemia
 Normal Wall thickness
 No systolic thickening
 Reduced Motion

81. Post Infarct

82. Post Infarct
 Thin echogenic wall
 No systolic thickening
 Reduced Motion

83. Dilated Cardiomyopathy

84. Paradoxic Septal Motion

85. Normal E point to septal separation is < 6 mm
With reduced lvef, EPSS may be increased.

89. help in differentiating pleural
effusion from pericardial
effusion
 If the ultrasonic beam is directed towards the left
atrium :
1)Gradual decrease in the echo free space–
pericardial effusion
2)Sudden cessation of echo free space- pleural
effusion

92. Quantitation of pericardial fluid can be done by m-mode echo,
but 2D-echocardiography gives a better idea esp. in c/o large or
loculated effusion

93. Cardiac tamponade- m
mode features
 Compressed RV (RVID<7mm)
 Increase in RV dimension with inspiration and
simultaneously decrease in LV dimension during
inspiration.
 Decrease mitral valve EF-slope with inspiration.
 Decrease mitral valve DE-amplitude with inspiration.
 RV diastolic collapse.(specific)
 RA diastolic collapse.(sensitive)
 Dilated IVC with blunted respiratory changes.

97. Cardiac tamponade- RV early
diastolic collapse

100. Constrictive pericarditis: m-
mode features
 Pericardial thickening
 Paradoxical septal motion
 Septal bounce( abrupt displacement of the IVS during early
diastole)
 Flattening of mid & late diastolic motion of the posterior
LV wall.
 Rapid early diastolic, or E-F, slope of the mitral valve.
 Rapid downward motion of the posterior aortic wall in
early diastole.
 Premature opening of pulmonary valve
 Dilated IVC with blunted respiratory changes.

103. Constrictive pericarditis-
septal bounce

106. Motion of the posterior aortic wall
reflects the filling and emptying patterns
of the left atrium.

107.  With impaired LA emptying, the aortic wall motion is
reduced during the rapid emptying phase, or the first third
of diastole.
 LA emptying index-
 If the first third of diastole does not represent at least 40%
of the total amplitude of the aortic wall motion during
diastole, then restriction to ventricular filling is suspected.

109. LA emptying index:
Decreased in c/o mitral stenosis
Increased in c/o mitral regurgitation

111. Color doppler m-mode
imaging
 Used to determine velocity of propagation (Vp) of LV
inflow.
 Determination of width of AR jet.
 Duration of MR.

112. Velocity of propagation

115. TAPSE (tricuspid annular plane
systolic excursion)

116. TAPSE – a measure for
assessing RV function
 TAPSE reference range 15 to 20mm
 Mildly abnormal- 13 to 15mm
 Moderately abnormal- 10 to 12mm
 Severely abnormal- <10mm

117. TAPSE