Zamboni Paolo, Sisini Francesco, Menegatti Erica, Taibi Angelo, Gadda Giacomo, Tavoni Valentina, Malagoni Anna Maria, Tessari Mirko, Gianesini Sergio, Gambaccini Mauro
Vascular Diseases Center, University of Ferrara, Cona, Ferrara, Italy.
Vascular Diseases Center, University of Ferrara, Cona, Ferrara, Italy; Department of Physics and Earth Sciences, University of Ferrara, Ferrara, Italy.
Ultrasound Med Biol. 2018 Mar;44(3):726-733. doi: 10.1016/j.ultrasmedbio.2017.11.001. Epub 2017 Dec 21.
The jugular venous pulse (JVP) is one of the main parameters of cardiac function and is used by cardiologists in diagnosing heart failure. Its waveform comprises three positive waves (a, c and v) and two negative waves (x and y). Recently, it was found that JVP can be extrapolated from an ultrasound (US) video recording of the internal jugular vein (IJV), suggesting its application in space missions, on which US scanners are already widely used. To date, the feasibility of assessing JVP in microgravity (microG) has not been investigated. To verify the feasibility of JVP assessment in microG, we tested a protocol of self-performed B-mode ultrasound on the International Space Station (ISS). The protocol consisted of a video recording of IJV synchronized with electrocardiogram that produces a cross-sectional area time trace (JVP trace) (in cm). The scans were acquired in six experimental sessions; two pre-flight (BDC1 and -2), two in space (ISS1 and -2) and two post-flight (Houston PF1, Cologne PF2). We measured the mean and standard deviation of the JVP waves and the phase relationship between such waves and P and T waves on the electrocardiogram. We verified that such parameters had the same accuracy on Earth as they did under microG, and we compared their values. The sensitivity, specificity and accuracy of JVP trace in microgravity are higher than those on Earth. The sequence of (a, c, and v) ascents and (x and y) descents along the cardiac cycle in microG is the same as that on Earth. The cause-and-effect relationship between the P and T waves on the electrocardiogram and a and v waves, respectively, of JVP is also confirmed in microG. Our experiment indicated the feasibility of deriving a JVP trace from a B-mode US examination self-performed by an astronaut in microG.
颈静脉搏动（JVP）是心功能的主要参数之一，心脏病专家用它来诊断心力衰竭。其波形包括三个正向波（a波、c波和v波）和两个负向波（x波和y波）。最近发现，可以从颈内静脉（IJV）的超声（US）视频记录中推断出JVP，这表明它可应用于太空任务，而超声扫描仪在太空任务中已被广泛使用。迄今为止，尚未研究在微重力（microG）环境下评估JVP的可行性。为了验证在微重力环境下评估JVP的可行性，我们在国际空间站（ISS）上测试了一种自我进行B超检查的方案。该方案包括一段与心电图同步的IJV视频记录，可生成横截面积时间轨迹（JVP轨迹）（单位为厘米）。扫描在六个实验阶段进行；两个飞行前阶段（BDC1和-2）、两个太空阶段（ISS1和-2）以及两个飞行后阶段（休斯顿PF1、科隆PF2）。我们测量了JVP波的均值和标准差，以及这些波与心电图上P波和T波之间的相位关系。我们验证了这些参数在地球上和微重力环境下具有相同的准确性，并比较了它们的值。微重力环境下JVP轨迹的敏感性、特异性和准确性高于在地球上。微重力环境下沿心动周期（a波、c波和v波）上升和（x波和y波）下降的顺序与地球上相同。微重力环境下也证实了心电图上的P波和T波分别与JVP的a波和v波之间的因果关系。我们的实验表明，宇航员在微重力环境下自我进行B超检查得出JVP轨迹是可行的。
