1. Noninvasive assessment of left internal mammary artery graft patency using transthoracic color doppler echocardiography before and after Dipyridamole infusion Noninvasive assessment of left internal mammary artery graft patency using transthoracic color doppler echocardiography before and after Dipyridamole infusion

2. Aim  Evaluation of the patency of LIMA on LAD by noninvasive transthoracic echocardiography

3. Patients :  34 patients ( 27 males, 7 females )  Mean age : 61± 4 yrs  CABG was done 4-11 yrs ago ( mean 7±2)  All patients undergoing coronary angiography because of recurrent anginal symptoms.  Doppler velocity profiles of LIMA were obtained in only 29 patients (because of techniqual problems).  34 patients ( 27 males, 7 females )  Mean age : 61± 4 yrs  CABG was done 4-11 yrs ago ( mean 7±2)  All patients undergoing coronary angiography because of recurrent anginal symptoms.  Doppler velocity profiles of LIMA were obtained in only 29 patients (because of techniqual problems).

4. Methods:  Echocardiography was performed using vingmed CFM 800 ultrasound unit and a 5 MHZ mechanical sector transducer.

5. LIMA detection  Patients were examined in left lateral decobitus position.  Using modified left parasternal view.  Long axis images of LV were obtained.  Patients were examined in left lateral decobitus position.  Using modified left parasternal view.  Long axis images of LV were obtained.

6.  Anterior of RVOT and anterior of interventricular sulcus was carefully examined by combined imaging and color flow mapping.  LIMA graft was identified as a tubular structure with color flow directed from base to apex.  Anterior of RVOT and anterior of interventricular sulcus was carefully examined by combined imaging and color flow mapping.  LIMA graft was identified as a tubular structure with color flow directed from base to apex.

7.  When the position of LIMA was identified, intraluminal flow signals were obtained using the pulsed doppler method

8. Six parameters were measured:  Peak systolic velocity  Peak diastolic velocity  Mean systolic velocity  Mean diastolic velocity  Systolic velocity time integral  Diastolic velocity time integral  Peak systolic velocity  Peak diastolic velocity  Mean systolic velocity  Mean diastolic velocity  Systolic velocity time integral  Diastolic velocity time integral

9.  Coronary angiography was done one day after echocardiography.  LIMA grafts were examined by using multiple projection and classified according to severity of LIMA Stenosis.  LAD after LIMA insertion was patent in all patients.  Coronary angiography was done one day after echocardiography.  LIMA grafts were examined by using multiple projection and classified according to severity of LIMA Stenosis.  LAD after LIMA insertion was patent in all patients.

10. Patient’s group according to angiographic findings:  Group 1 : LIMA was patent or had non significant stenosis.  Group 2 : LIMA had significant (>70%) stenosis.  Group 1 : LIMA was patent or had non significant stenosis.  Group 2 : LIMA had significant (>70%) stenosis.

11.  In all of patients, doppler velocity profile of LIMA was recorded before and after injection of dipyridamole.

12. Angiographic results  LIMA graft was patent in 12 patients.  LIMA graft had nonsignificant stenosis in 7 patients.  LIMA graft had significant stenosis in 10 patients.  LIMA graft was patent in 12 patients.  LIMA graft had nonsignificant stenosis in 7 patients.  LIMA graft had significant stenosis in 10 patients.

13. Echocardiographic results  In all cases, there was biphasic pattern of blood flow corresponding to systole and diastole.  Two different pattern were observed.  In all cases, there was biphasic pattern of blood flow corresponding to systole and diastole.  Two different pattern were observed.

14. In group 1 :  Who had normal graft or moderate stenosis, flow was dominant during diastole. Dipyridamole induced an increase in diastolic flow in this group more than group 2.

15. Diastolic flow pattern of LIMA in group 1

16. In group 2:  Who had an occluded or severely stenosed LIMA graft. Flow was dominant during systole and low velocity profile were recorded during diastole.  Dipyridamole induced an increase in diastolic flow in this group lower than group 1.  Who had an occluded or severely stenosed LIMA graft. Flow was dominant during systole and low velocity profile were recorded during diastole.  Dipyridamole induced an increase in diastolic flow in this group lower than group 1.

17. Systolic flow pattern of LIMA in group 2

18. Advantages of this method:  Noninvasive  Inexpensive  Easy  Noninvasive  Inexpensive  Easy

19. Disadvantages of this method:  If significant stenosis of LAD after insertion of LIMA was present, LIMA flow pattern become similar to that LIMA stenosis.  In obese patients, LIMA flow pattern was not easily taken.  If significant stenosis of LAD after insertion of LIMA was present, LIMA flow pattern become similar to that LIMA stenosis.  In obese patients, LIMA flow pattern was not easily taken.

20. Result:  The echocardiographic evaluation of LIMA is a simple, noninvasive method for the assessment of the graft patency.  Dipyridamole infusion also increase diastolic flow pattern in patent LIMA rather than stenosed LIMA.  The echocardiographic evaluation of LIMA is a simple, noninvasive method for the assessment of the graft patency.  Dipyridamole infusion also increase diastolic flow pattern in patent LIMA rather than stenosed LIMA.