Changes in left ventricular size during parabolic flights by two-dimensional echocardiography and level set method.
This study aims to evaluate changes on cardiac chambers size, induced by gravitational stresses. During parabolic flight, seven subjects underwent 2-D transthoracic echocardiography at three different gravity phases (1 Gz, 1.8 Gz, and 0 Gz). LV endocardial borders were detected applying a semi-automatic segmentation procedure based on level set methods. LV cavity area was computed frame-by-frame for a whole cardiac cycle during each gravity phase. Expected modifications in LV area with different gravity were found: at 1.8 Gz, end-diastolic (ED) and end-systolic (ES) areas were significantly (p<0.05) reduced of 10.7 +/- 5.4% and 21.6 +/- 11.1% respectively, compared to 1 Gz values, while they were increased of 11.2 +/- 5.4% and 11.1 +/- 6% during 0 Gz. Fractional area change was augmented of 20.9 +/- 29.1% at 1.8 Gz, while it remained unchanged at 0 Gz, compared with 1 Gz values. Furthermore, LV filling due to atrial contraction was increased at 0 Gz of 39 +/- 35.6%.
Corsi
C
C
DEIS University of Bologna, Bologna, Italy.
Saracino
G
G
Lamberti
C
C
Cerutti
S
S
Bailliart
O
O
Cholley
B
B
Capderou
A
A
Vaida
P
P
Caiani
E G
EG
D000328:Adult; D000465:Algorithms; D004452:Echocardiography; D005240:Feasibility Studies; D006112:Gravitation; D006325:Heart Atria / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D006352:Heart Ventricles / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D006801:Humans; D018471:Hypergravity; D007091:Image Processing, Computer-Assisted; D008875:Middle Aged; D013026:Space Flight; D014893:Weightlessness