Mechanical Function of Internal Jugular Vein Valve: Post-analysis of M-Mode Imaging under Cardiac Monitoring

Because the internal jugular vein (IJV) valve is the only protective valve between the brain and heart, recent studies have focused on the dynamic behaviour of the valve and its importance in regulating the cerebral blood outflow pathway. However, the mechanism underlying valve opening and closure, as well as the normal opening time, has not been investigated before. The aim of the study described here was to investigate IJV physiology in healthy young adults by means of ultrasound imaging. Twenty-four normal young adults (16 male, 8 female, 21.79 ± 0.79 y of age) were enrolled in this study. Each participant underwent IJV B- and M-mode ultrasound scans of the neck veins in supine position. Data on IJV leaflet movement and IJV blood velocity were extracted from images with the associated electrocardiogram traces to analyze the opening and closure cycles of IJV leaflets. The normal opening time calculated in this study includes 70% of the dynamic valve cycle. The normal opening time of the IJV valve could be a new physiologic metric and serves as a premise for further studies in the field of cerebral venous return.