5th Conference of the European Study Group on Cardiovascular Oscillations

The European Space Agency (ESA) Short-Arm Centrifuge (SAHC) was used to generate 0.7, 1, and 1.2 Gz of artificial gravity at the level of the heart in 6 healthy male subjects. We investigated the hypothesis that the effects of hyper-gravity on Respiratory Sinus Arrhythmia (RSA) can mimic the effects observed after spaceflight cardiovascular deconditioning. Artificial gravity along the head-to-feet axis on a short-arm centrifuge induces gravity gradients. This physiological condition is new and with higher g at the feet than at heart level induces blood sequestration in the lower limbs. Astronauts are after spaceflight are in a condition of cardiovascular deconditioning where blood pooling in the legs or autonomic adaptation are factors contributing to orthostatic intolerance and changes in HRV. ECG and respiration were recorded during Imposed and Controlled Breathing (ICB) protocols which were repeated at different levels of artificial gravity as well as during supine and standing control measurements. RSA was studied with a time domain method suitable for the analysis of very short recordings. Results obtained on the centrifuge were compared to results from a previous study analyzing changes in HRV and RSA during similar ICB protocols during and after a short-duration (11 days) spaceflight mission.