Evaluation of cardiovascular hemodynamics in response to recumbent positions by using magnetic resonance imaging

Abstract

Limited research has been performed to clarify hemodynamic response to different positions, namely the supine, left recumbent, and right recumbent positions. In general, magnetic resonance imaging (MRI) has been reported to be more reliable and reproducible technique than an ultrasound scan for accurate assessment of hemodynamics. Our aim was to evaluate whether the left and right recumbent positions affect cardiovascular hemodynamics compared with the supine position by using MRI assessment. Between June 2017 and August 2017, 12 healthy men aged 26.8 ± 3.1 years were recruited in this study. We measured the following parameters in each posture: heart rate (HR), stroke volume index (SI), cardiac index (CI) in the left ventricle using cine‐MRI, and blood flow velocity and blood volume in the superior vena cava (SVC) and inferior vena cava (IVC) using phase‐contrast MRI. After lying in the supine position, the participants maintained each recumbent position in random order at an angle of approximately 45°. The HR in the left recumbent position and SI in the right recumbent position were observed to be the lowest among those in the other positions. In both recumbent positions, CI tended to decrease compared to that in the supine position. In the right recumbent position, blood volume in the SVC and IVC was significantly lower than that in the supine position. These results suggest that a low HR in the left recumbent position and low blood volume in the right recumbent position result in a decrease in CI in both the right and left recumbent positions.Support or Funding InformationThis work was supported in part by a grant from North Japan Academy of Nursing Science.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.