Assessment of jugular venous pulse during walking by wearable strain-gauge plethysmograph: a pilot study

The jugular venous pulse (JVP) is a fundamental parameter of cardiac function. Recently a non-invasive method to record JVP waveform by means of wearable strain-gauge plethysmography was used to trace JVP in healthy subjects. This device was never used to monitor exercise up to now. The aim of the present investigation is indeed to study the potential information of JVP during exercise. Ten healthy volunteers underwent to exercise, and they were monitored by a wireless plethysmograph synchronized with electrocardiogram (ECG). The measurements were collected during different activities: in supine and upright position and during aerobic exercise. The JVP waves were recorded, analyzed and the potential physiologic information were investigated. The focus was on
$a$
and
$x$
peaks of the JVP waveform, since they correspond to atrial and ventricular contraction, respectively. Moreover, the analysis focused on the amplitude difference between
$a$
and
$x$
peaks (Δax), which is correlated with the pressure gradient between the two cardiac phases. Significant differences in the values of a, x and Δax during standing and walking was found compared to the values measured in supine position, which was considered as a reference. The consistent variation of the JVP during different activities might provide useful information on both cardiac filling and venous return efficiency. Further studies are encouraged in order to compare the JVP waveforms during different exercises.