On the relationship between competitive flow and FFT analysis of the flow waves in the left internal mammary artery graft in the process of CABG.
BACKGROUND
During coronary artery bypass grafting (CABG), the ratio of powers of the fundamental frequency and its first harmonic (F0/H1) in fast Fourier transformation (FFT) analysis of the graft's flow waves has been used in the field of evaluation of the patency in anastomosis. But there is no report about using the FFT method to evaluate the magnitude of competitive flow. This study is aiming at exploring the relationship between competitive flow and FFT analysis of the flow waves in left internal mammary artery (LIMA) graft, and finding a new method to evaluate the magnitude of competitive flow.


METHODS
At first, establishing the CABG multiscale models of different stenosis in left anterior descending artery (LAD) to get different magnitude of competitive flows. Then, calculating the models by ANSYS-CFX and getting the flow waves in LIMA. Finally, analyzing the flow waves by FFT method and comparing the FFT results with the magnitude of competitive flow.


RESULTS
There is no relationship between competitive flow and F0/H1. As for F0/H2 and F0/H3, they both increase with the reduction of the stenosis in LAD. But the increase of F0/H3 is not obviously enough and it can't identify the significant competitive flow clearly, so it can't be used as the evaluation index. It is found that F0/H2 increases obviously with the increase of the competitive flow and can identify the significant competitive flow.


CONCLUSIONS
The FFT method can be used in the evaluation of competitive flow and the F0/H2 is the ideal index. High F0/H2 refers to the significant competitive flow. This method can be used during CABG to avoid the risk of competitive flow.
College of Life Science and Bio-engineering, Beijing University of Technology, Beijing, China.
Boyan
B
Mao
College of Life Science and Bio-engineering, Beijing University of Technology, Beijing, China.
Wenxin
W
Wang
Peking University People's Hospital, Beijing, China.
Zhou
Z
Zhao
College of Life Science and Bio-engineering, Beijing University of Technology, Beijing, China.
Xi
X
Zhao
College of Life Science and Bio-engineering, Beijing University of Technology, Beijing, China.
Lanlan
L
Li
College of Life Science and Bio-engineering, Beijing University of Technology, Beijing, China.
Huixia
H
Zhang
College of Life Science and Bio-engineering, Beijing University of Technology, Beijing, China. lyjlma@bjut.edu.cn.
Youjun
Y
Liu
D001783:Blood Flow Velocity; D003198:Computer Simulation; D017023:Coronary Angiography; D001026:Coronary Artery Bypass / Q000379:methods*; D003326:Coronary Circulation; D023921:Coronary Stenosis; D003331:Coronary Vessels; D005583:Fourier Analysis; D006083:Graft Occlusion, Vascular; D006439:Hemodynamics; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D008297:Male; D008323:Mammary Arteries / Q000503:physiopathology*; D008955:Models, Cardiovascular; D018608:Ultrasonography, Doppler
CABG; Competitive flow; FFT