The method for evaluating cardiac function by echocardiography

1. The method for evaluating cardiac function by echocardiography 10. 16. 2008. 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. 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) Normal Anterior MI

14. Abnormality of LV wall motion in acute myocardial infarction (apical view) Normal 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 × Σ rn2 × LVEF (Simpson’s method) = 20 4 r1,2,3,・・・ End-diastolic phase End-systolic phase

17. The method of evaluating echocardiographic data 1. Download image analyzing software. Image J: http://rsbweb.nih.gov/ij/ (Windows, Mac OS X) Scion image: http://www.scioncorp.com/ (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