1. The method for evaluating cardiac function by echocardiography
Research Meeting
Yasuhiro Maejima MD, PhD

2. The features of echocardiography
1. Echocardiography is used to diagnose cardiovascular diseases. In fact, it is one of the most widely used diagnostic tests for heart disease. It can provide a wealth of helpful information, including the size and shape of the heart, its pumping capacity and the location and extent of any damage to its tissues.
2. It is especially useful for assessing diseases of the heart as follows:
(1) Coronary artery disease: wall motion, systolic function
(2) Cardiomyopathy (hypertrophic, dilated, etc): wall thickness, systolic function
(3) Valvular heart disease: valvular dysfunction (stenosis, regurgitation)
(4) Others: Pericardial diseases, Aortic diseases, Pulmonary vascular diseases
3. The biggest advantage to echocardiography is that it is noninvasive (doesn't involve breaking the skin or entering body cavities) and can do repeatedly.

3. M-mode & 2-D echocardiography
Ultrasound is an acoustic wave with a frequency higher than 20 kHz.
Echocardiography: 2.5〜3.5MHz (Human), 10〜12.5MHz (Mouse)
An echocardiogram is a recording of the reflected ultrasonic beam.There are two major types of echocardiography: M-mode and two-dimensional (2-D).
In the M-mode, a single beam of ultrasound is used. The reflections of the signal are recorded and displayed as monochronic dots. The location is proportional to the distance from the reflective region, and the intensity contains the information about acoustic impedance of the region. The M-mode has excellent axial resolution, but it carries essentially one-dimensional information.
The 2-D echocardiograph typically uses a multielement transducer, which generates a single ultrasonic beam with changing direction. This technique allows one to create a two-dimensional image, which has good lateral resolution but lacks accuracy in the axial dimension.

4. 2-D Echocardiography

5. Long axis view of the heart (Human)
Interventricular septum
Aorta
Left ventricle
Right ventricle
Aortic valve
Mitral valve
Left atrium

6. Right ventricle
Left ventricle
Aortic valve
Mitral valve
Left atrium

7. Long axis view of the heart in 2-D echocardiography (Mouse)
Right ventricle
Left ventricle
Aorta
Mitral valve
Left atrium

8. Short axis view of the heart
Middle portion
Right ventricle
Interventricular septum
Left ventricle
Left ventricle
Papillary muscle
Apical portion

9. 2-D short axis image M-mode image Right ventricle Papillary muscle
Left ventricle
2-D short axis image
M-mode image

10. 2-D image → M-mode image
Human
Mouse

11. Measurement parameters of left ventricle
Right ventricle diameter
End-diastolic septal wall thickness
(DSEP WT)
End-systolic septal wall thickness
(SSEP WT)
End-diastolic left ventricular diameter
　　 （ＬVEDD）
End-systolic left ventricular diameter 　　 （ＬVEDD）
End-diastolic posterior wall thickness
(DPW WT)
End-systolic posterior wall thickness
(SPW WT)

12. Left ventricular ejection fraction (LVEF)
When we evaluate LVEF by M-mode echocardiography, we regard the heart as a oval solid of revolution. So we measure LVEDD and LVESD and then calculate an approximate value of LVEF by the formula as described below:
End Systolic Volume - End Diastolic Volume
LVEF =
× 100
End Diastolic Volume
7× LVEDD3
7× LVESD3 -
2.4 + LVEDD
2.4 + LVESD =
× 100
7× LVEDD3
2.4 + LVEDD
(Teicholz LE et al. Am J Cardiol. 1976)

13. Abnormality of LV wall motion in acute myocardial infarction (short axis view)
Anterior MI

14. Abnormality of LV wall motion in acute myocardial infarction (apical view)
Anterior MI

15. Images of mouse heart in acute myocardial infarction
Long axis
M-mode

16. Alternative ways of evaluating LV systolic function
LVEDD - LVESD
Left ventricular fractional shortening (%FS) =
× 100
LVEDD
(Quinones MA et al. Chest. 1978) L π L
LVEF (Simpson’s method) =
× Σ rn2 × 4 20
r1,2,3,・・・
End-diastolic phase
End-systolic phase

17. The method of evaluating echocardiographic data
1. Download image analyzing software.
Image J: (Windows, Mac OS X)
Scion image: (Windows Xp)
2. Open the data file that was made by Excel file.
3. Input the information
about your mice in
the data file
(red letters).

18. 4. Open the raw data sent from Shumin by image
analyzing software (“.bmp” file).
5. Click “Point selections” button (Image J).

19. 6. To begin analyzing the echo data, click on the picture of
raw data, push “Ctrl +M” button, and then you can see the
table of “Results”. ① ② ③ ③
①＆②

20. 7. Click the specific point that indicates DSEP WT, LVEDD,
DPW WT, SSEP WT, LVESD and SPW WT on the raw data
and repeat this process for three times.

21. Re:Measurement parameters of left ventricle
DSEP WT
SSEP WT
ＬVEDD
ＬVEDD
DPW WT
SPW WT

22. 8. Click the specific point that indicates R-R interval, time and
length on the raw data as described below:
② Time (0.2 sec): 2 points
① R-R interval: 4 points
③ Length (10 mm)R-R: 2 points

23. 10. Copy the data of “X and Y” values from “Results” table.
Then, paste that data on the specific area of data file.
→ We can get ECHO DATA !

24. Notice for evaluating echo data in M-mode
When you evaluate echocardiographic data, be careful for confusing structures that is easy to mistake for LV wall: valves, papillary muscles.
False (part of mitral valve)
True posterior wall