1. 1. Dr. Amit Kumar Senior Resident, Department of Cardiology R.N.T Medical College Udaipur , India
2. 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 couldnt be underestimated even in presence of 2D ,3D, real time 3D, or doppler echocardiography.
3. 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
4. 4. 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.
5. 5. M-mode echocardiography is use to evaluate the morphology of structures ; movement and velocity of cardiac valves and walls; and timing of cardiac events.
6. 6. M-mode Evaluation Amplitude Velocity Time intervals Morphology
7. 7. Amplitude = Y2 Y1 Y1 Y2 Amplitude Measurement Distance Time
8. 8. Time interval = T2 T1 T2T1 Time Measurement Distance Time
9. 9. dy = Y2 Y1 Y1 Y2 Slope Measurement T1 T2 dt = T2 T1 Slope = dy/dt = velocity
10. 10. M-mode at the Mitral Valve The mitral valve has 2 leaflets anterior and posterior.
11. 11. 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.
12. 12. Mitral Stenosis
13. 13. 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.
14. 14. 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.
15. 15. Flail mitral leaflet : m-mode features Coarse diastolic fluttering of mitral leaflets. Flail mitral leaflet may appear within LA
16. 16. Infective endocarditis: m- mode features Valve leaflet appear thickened, smudged, shaggy. Vegetation on a valve leaflet usually doesnt restrict valve motion.
17. 17. Mitral Valve Endocarditis
18. 18. 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
19. 19. Premature closure of Mitral valve: m-mode features When C-point of the mitral valve occurs before the onset of the QRS complex.
20. 20. Fluttering of AML in aortic regurgitation
21. 21. B bump due to elevated EDP B-bump or notch
22. 22. Hypertrophic Cardiomyopathy Systolic anterior motion of mitral valve s/o dynamic LVOT obstruction
23. 23. 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.
24. 24. M-mode at the Aortic Valve Coronary cusp Non-coronary cusp Anterior aortic root Posterior aortic root Left Atrium
25. 25. M-mode at the Aortic Valve LA dimension Cusp Separation (1.5-2.5cms in adult) Aortic root
26. 26. M-mode at the Aortic Valve LA dimension Measurements are made from leading edge to leading edge.
27. 27. Aortic stenosis: m-mode features Thickening valve leaflets. Decreased excursion of valve leaflet. Absence of systolic flutter of aortic valve leaflet.
28. 28. Critical Aortic Stenosis
29. 29. M-mode at the Aortic Valve Bicuspid Valve Eccentric closure line Seen when there is a Bicuspid aortic valve
30. 30. 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.
31. 31. Fluttering of AML in aortic regurgitation
32. 32. Premature opening of Aortic valve in AR
33. 33. Diastolic fluttering of aortic valve in AR
34. 34. coarse fluttering of aortic valve cusp- SUBAORTIC MEMBRANE
35. 35. 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
36. 36. Systolic notching of AV in HCM
37. 37. 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
38. 38. 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.
39. 39. M-mode at Pulmonary valve
40. 40. Pulmonary stenosis m-mode feature- increase depth of pulmonary valve a wave (increased a-dip)
41. 41. Pulmonary HTN with Flying W sign Pulmonary hypertension m-mode feature- loss of A-dip of pulmonary valve
42. 42. M-mode at tricuspid valve
43. 43. M-mode at Left Ventricle RVWT
44. 44. M-mode at Left Ventricle RVIDd
45. 45. M-mode at Left Ventricle IVSd
46. 46. M-mode at Left Ventricle LVIDd
47. 47. M-mode at Left Ventricle LVPWd
48. 48. M-mode at Left Ventricle IVS excursion
49. 49. M-mode at Left Ventricle IVSs
50. 50. M-mode at Left Ventricle LVIDs
51. 51. M-mode at Left Ventricle LVPWs
52. 52. M-mode at Left Ventricle LVPW excursion
53. 53. FS EF LV mass M-mode LV Calculation
54. 54. M-mode LV Calculation FS = LVIDd LVIDs LVIDd
55. 55. M-mode LV Calculation EF = LVIDd3 LVIDs3 LVIDd3
56. 56. M-mode LV Calculation LV Mass = 1.04 {(LVIDd + IVSd + LVPWd)3 (LVIDd)3} x 0.8 + 0.6g
57. 57. 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%
58. 58. 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