Characterization and quantification of vortex flow in the human left ventricle by contrast echocardiography using vector particle image velocimetry.
OBJECTIVE
The aims of this study were to: 1) assess the feasibility of left ventricular (LV) vortex flow analysis using contrast echocardiography (CE); and 2) characterize and quantify LV vortex flow in normal subjects and patients with LV systolic dysfunction.


BACKGROUND
Vortices that form during LV filling have specific geometry and anatomical locations that are critical determinants of directed blood flow during ejection. Therefore, it is clinically relevant to assess the vortex flow patterns to better understand the LV function.


METHODS
Twenty-five patients (10 normal and 15 patients with abnormal LV systolic function) underwent CE with intravenous contrast agent, Definity (Bristol-Myers Squibb Medical Imaging, Inc., North Billerica, Massachusetts). The velocity vector and vorticity were estimated by particle image velocimetry. Average vortex parameters including vortex depth, transverse position, length, width, and sphericity index were measured. Vortex pulsatility parameters including relative strength, vortex relative strength, and vortex pulsation correlation were also estimated.


RESULTS
Vortex depth and vortex length were significantly lower in the abnormal LV function group (0.443 +/- 0.04 vs. 0.482 +/- 0.06, p < 0.05; 0.366 +/- 0.06 vs. 0.467 +/- 0.05, p < 0.01, respectively). Vortex width was greater (0.209 +/- 0.05 vs. 0.128 +/- 0.06, p < 0.01) and sphericity index was lower (1.86 +/- 0.5 vs. 3.66 +/- 0.6, p < 0.001) in the abnormal LV function group. Relative strength (1.13 +/- 0.4 vs. 2.10 +/- 0.8, p < 0.001), vortex relative strength (0.57 +/- 0.2 vs. 1.19 +/- 0.5, p < 0.001), and vortex pulsation correlation (0.63 +/- 0.2 vs. 1.31 +/- 0.5, p < 0.001) were significantly lower in the abnormal LV function group.


CONCLUSIONS
It was feasible to quantify LV vorticity arrangement by CE using particle image velocimetry in normal subjects and those with LV systolic dysfunction, and the vorticity imaging by CE may serve as a novel approach to depict vortex, the principal quantity to assess the flow structure.
Hong
Geu-Ru
GR
Ohio State University, Columbus, Ohio 43210, USA.
Pedrizzetti
Gianni
G
Tonti
Giovanni
G
Li
Peng
P
Wei
Zhao
Z
Kim
Jin Kyung
JK
Baweja
Abinav
A
Liu
Shizhen
S
Chung
Namsik
N
Houle
Helene
H
Narula
Jagat
J
Vannan
Mani A
MA
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003287:Contrast Media; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D005466:Fluorocarbons; D005583:Fourier Analysis; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011673:Pulsatile Flow; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016277:Ventricular Function, Left
D003287:Contrast Media; D005466:Fluorocarbons; C042852:perflutren