Di Rienzo Marco, Castiglioni Paolo, Meriggi Paolo, Rizzo Francesco, Trivelloni Pierandrea, Cacopardo Salvatore, Guadagno Anton Giulio
Dept. of Biomedical Technology, "Santa Maria Nascente" Research Hospital, Fondazione Don Carlo Gnocchi, 20148 Milan, Italy.
Annu Int Conf IEEE Eng Med Biol Soc. 2010;2010:3457-9. doi: 10.1109/IEMBS.2010.5627874.
The Push-Pull Effect (PPE) is a physiological phenomenon defined as a reduction of +Gz tolerance induced by a previous exposure to a -Gz acceleration, that may lead to loss of consciousness. Aim of this study was to evaluate, for the first time, the cardiac rhythm changes associated with PPE during real flights. Data were collected in 3 pilots during flights on the Aermacchi MB- 339-CD aircraft. In each flight, lasting about 60 minutes, ECG, respiration and 3D accelerations were recorded by a new smart garment (the MagIC System). The flight protocol included a maneuver eliciting a reference +5Gz acceleration for 15 seconds (Ref+5G), followed, after a while, by a push-pull maneuver with a profile characterized by a 5-s acceleration at -1Gz (PP-1G) and, with a 1G/s onset, by 15 seconds at +5Gz (PP+5G), so to induce the push-pull gravitational stress. From each ECG recording, a beat-by-beat RR Interval (RRI) series was derived. RRI mean, standard deviation (SDNN) and the RRI Root Mean Square of Successive Difference (RMSSD) were estimated in each pilot during the Ref+5G and the PP+5G maneuvers. As compared with Ref+5G, all pilots displayed significant reductions in RRI mean, SDNN and RMSSD during PP+5G. These findings are compatible with a PP-induced enhancement in the sympathetic drive to the heart -as shown by the reduction in RRI mean and SDNN- and a concomitant deactivation of the parasympathetic control as shown by the reduction in RMSSD.
推拉效应（PPE）是一种生理现象，定义为先前暴露于 -Gz 加速度所导致的 +Gz 耐力降低，这可能会导致意识丧失。本研究的目的是首次评估实际飞行过程中与推拉效应相关的心律变化。在 3 名飞行员驾驶阿梅马基 MB - 339 - CD 飞机飞行期间收集了数据。在每次持续约 60 分钟的飞行中，通过一种新型智能服装（MagIC 系统）记录心电图、呼吸和三维加速度。飞行方案包括一个引发 15 秒参考 +5Gz 加速度的机动动作（Ref + 5G），一段时间后，接着是一个推拉机动动作，其特征为在 -1Gz 下有 5 秒的加速度（PP - 1G），并以 1G/s 的起始加速度，在 +5Gz 下持续 15 秒（PP + 5G），从而诱发推拉重力应激。从每次心电图记录中得出逐搏 RR 间期（RRI）序列。在 Ref + 5G 和 PP + 5G 机动动作期间，对每位飞行员的 RRI 平均值、标准差（SDNN）和逐次差值的 RRI 均方根（RMSSD）进行了估计。与 Ref + 5G 相比，所有飞行员在 PP + 5G 期间的 RRI 平均值、SDNN 和 RMSSD 均显著降低。这些发现与推拉效应导致的心脏交感神经驱动增强（如 RRI 平均值和 SDNN 的降低所示）以及副交感神经控制的相应失活（如 RMSSD 的降低所示）相一致。
