Changes in LV function during parabolic flight: preliminary results

Parabolic flight induces modifications on left ventricular (LV) dimensions. By 2-D echocardiography we studied these changes induced by gravitational stresses. A semi-automatic LV endocardial border detection procedure based on level set methods was applied and LV cavity area computed frame-by-frame for a whole cardiac cycle during each gravity phase (1 Gz, 1.8 Gz, and 0 Gz). 8 subjects were studied during parabolic flights. Reliable contours were detected in 88% (43/49) of the processed frames. In the analyzed subject, at 2 Gz end-diastolic (ED) and end-systolic (ES) areas were reduced of 17% and 35%, in respect to 1 Gz, while they were increased of 21% and 9% respectively during 0 Gz. LV filling due to atrial contraction doubled at 0 Gz (53%) compared to 2 Gz (27%). The proposed method was able to detect the dynamic changes in LV area obtained at different gravity conditions. Further analysis is required on the whole population to obtain significant values of induced changes.