Semiautomated analysis of Doppler images for quantification of changes in mitral inflow pattern during parabolic flight

To study changes in left ventricular (LV) mitral inflow induced by gravitational stresses, and evaluate the effects due to different postures, we performed transthoracic Doppler imaging during parabolic flights on 7 normal subjects (mean age□SD, 46±5 years) in standing upright and resting position. To detect Doppler velocity profiles, a semiautomatically procedure based on local image properties, was applied. Then, LV inflow parameters were automatically computed and their modifications according to different gravity conditions were found: in standing, LV diastolic rapid filling parameters were significantly affected (E-wave peak, cm/s: from 54.7±11.1 at 1G to 85.8±12.1 at 0G; E-wave integral, cm: from 6.6±1.7 at 1G to 13.1±3.2 at 0G; E/A integral ratio, a.u.: from 1.4±7 at 1G to 2.5±8 at 0G), while late diastolic filling parameters were preserved (A-wave peak, cm/s: from 48.8±3.6 at 1G to 55.3±11.3 at 0G). No changes were noted while subjects were in supine resting.