Ultrasound examination of vertebral artery of the pilots grounded due to syncope

Objective To learn vertebral artery hemodynamic abnormality and congenital dysplasia of the military pilots grounded due to syncope.Methods Sixty-six grounded pilots due to syncope were chosen as grounded group while other 70 normal pilots were taken as control group.The ultrasound examinations of vertebral artery were retrospectively reviewed and analyzed.Results In grounded group 37 showed vertebral artery abnormality,included 27 cases of peak systolic velocity reduction and 32 cases of blood flow volume decreased.The inner diameter of vertebral artery was less than or equal to 3.0 mm in 29 cases,in which 5 cases' was less than or equal to 2.5 mm and 6 cases showed abnormal vertebral artery shape.The average value of vertebral artery diameter,peak systolic velocity and flow volume of control group was respectively lower than that of grounded group.Comparing with control group,grounded group showed significant differences on left vertebral artery diameter,as well as the peak systolic velocity and flow volume of left and right artery except right vertebral artery diameter (t=4.048-7.223,P＜0.01).But there was no statistical difference between the parameters of left and right vertebral artery in grounded group.45.5％ pilots of grounded group were found having concurrent cervical vertebrae changes which were checked out by X-ray examination.Conclusions The vertebral artery congenital dysplasia takes lower proportion in syncope-induced grounded pilots but the vertebral artery hemodynamic abnormality-such as reduction of peak systolic velocity and reduction of blood flow volume.And the concurrent cervical vertebrae changes are relatively frequent in those pilots.Pilot's cervical spine protection and exercise should be paid more attention and the vertebral artery ultrasound examination is suggested to be included in the pilot recruitment examination as soon as possible. Key words: Vertebral artery; Ultrasonography,Doppler,color; Syncope; Retrospective studies