Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]
Overview
One-dimensional or M-mode echocardiography is one beam of ultrasound directed toward the heart.
Historical Perspectives
One of the first modes available
Excellent resolution
Keys to interpretation
What structure is being imaged?
Where is the cursor?
Size
Septum in HOCM
Timing
Tamponade – diastolic collapse
Density
Myxomatous leaflets, masses
Technology
A single crystal rapidly alternates between transmission and receiver modes with rapid updating result, rapidly moving structures (eg, valve leaflets) can be monitored for their characteristic motion very high temporal resolution
Specific Structures
During systole do the aortic valve leaflets oppose the aorta?
Are the leaflets thick and calcified (bright)?
Possible to have normal appearance on m-mode if non-calcific
Are leaflets open throughout systole – HOCM, low-output state
Aortic M-Mode
Anterior leaflet with E/A appearance of diastology
Decreased EF slope in MS
Scalloping of leaflet tip in end systole in prolapse
Mitral M-Mode
Ventricular M-mode
Ventricular Wall Thickness
Ventricular Chamber Size
Intraventricular Masses
Ventricular M-Mode
M Mode Pathologic States
Thickened, calcified leaflets
Dense, persistent echoes replacing the normal motion patterns
Post-stenotic aortic root dilation (> 35mm)
LVH
Eccentrically placed diastolic closure line (BAV)
Aortic Stenosis M Mode
Systolic bowing of the posterior mitral valve leaflet
MVP M Mode
Septal hypertrophy
Systolic anterior motion (SAM) of the anterior mitral valve leaflet
Mid-systolic (premature) closure of the aortic valve due to outflow track obstruction
HOCM M Mode
HOCM Mid Systolic AV Closure
HOCM M Mode
Leaflet tips bright (calcified) and thickened
E/F slope decreased
Mitral Stenosis M Mode
Diastolic collapse of the right ventricle
Tamponade M Mode
Tamponade M Mode
Increased duration between E and A peaks
Fluttering of the anterior mitral valve leaflet due to AI jet turbulence
Clinical setting to decide mechanism
Aortic Regurgitation M Mode
Other M Mode Findings
B Bump
Elevated left ventricular end diastolic pressure
B Bump
Thickened leaflets
Good motion
Mass
Clinical scenario likely to give clue – dialysis patient, etc.
Aortic Valve Endocarditis M Mode
Bright hyperdensity in mitral orifice throughout cardiac cycle
Functional MS
Left Atrial Myxoma M Mode
M-mode of pulmonary valve – W appearance indicates elevated pulmonary pressures
Hypertensive Heart Disease M Mode
Mitral Stenosis M Mode
MItral Valve Prolapse.jpg M Mode
Flail Posterior Mitral Leaflet M Mode
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