Different patterns of longitudinal displacement of the common carotid artery wall in healthy humans are stable over a four-month period.

Using an in-house developed ultrasonic method, we have shown that there is distinct longitudinal multiphasic displacement of the human common carotid artery (CCA) wall during the cardiac cycle. Different subjects showed markedly different patterns of displacement. At present, it is not known if the pattern of displacement in an individual is stable over time. Therefore, in this study, we measured the longitudinal displacement of the right CCA in 10 healthy humans at two different occasions 4 months apart. The basic pattern of longitudinal displacement for an individual was highly stable, including intraclass correlation coefficient (ICC) of 0.88 for the ratio between the first antegrade and the retrograde displacement, and ICC of 0.76 for the magnitude of the first antegrade displacement. The stable basic pattern of displacement showed marked differences among subjects, also of the same age and gender. Further studies are needed to elucidate the underlying mechanisms, the physiologic, pathophysiologic and clinical implications of this phenomenon.