| 【Objective】 The objectives of this study were to(1)measure the TDI spectrum of vessel wall and the flow spectrum of Doppler at the same level simultaneously,(2)compare whether the two pulse waves were synchronized or not,(3)analyze the characters of pulse wave propagation in vessel wall and flow as well as the factors affecting them,and(4)investigate the time difference of pulse wave propagation in vessel wall and flow between healthy volunteers and patients with atherosclerosis and analyze its mechanism by using dual pulsed-wave Doppler echocardiography.【 Methods 】 A total of 105 subjects who underwent vascular ultrasound examination in The People’s Liberation Army Joint Service Support Force No.967 Hospital from December 2018 to September 2019 were selected as the screening target population,consisting of 64 healthy volunteers(including 27 controls)and 41 subjects with high blood pressure and(or)diabetes.There were 75 males and 30 females in the screening target population,with an average age of 46 ± 20 year.The general ultrasonic data of carotid artery,femoral artery and popliteal artery(vessel diameter,intima-media thickness,flow velocity and resistance index)were measured by using the HI VISION Preirus ultrasonic diagnostic instrument of HITACHI(Japan)and electrocardiogram(ECG)was recorded synchronously.The two spectra of TDI and flow Doppler of carotid artery,femoral artery and popliteal artery were recorded by using dual pulsed-wave Doppler echocardiography.Sample volumes of TDI and flow Doppler were set in vessel wall and flow,respectively,and they were at the same level.And time difference(Δ t)between the starting points of two spectra was measured.Then,sample volumes of were set at the anterior wall and posterior wall of carotid artery,femoral artery and popliteal artery,the two spectra of TDI were recorded,and time difference(Δt)between the starting points of two spectra was measured as well.The peak flow velocity of the ascending aorta,left ventricular ejection time and left ventricular ejection fraction were measured.Finally,general clinical data of subjects were recorded: height,weight,heart rate,blood pressure,blood glucose,total cholesterol,triglycerides,low-density lipoprotein(LDL)and high-density lipoprotein(HDL).Whether the time difference existed or not and correlations of time difference to other factors were analyzed.【Results】1.The onset of artery wall distension waveform(the onset of systolic upslope in the TDI spectrum)occurred earlier than the onset of blood velocity waveform obtained from flow Doppler signal in all the arteries(a total of 105 subjects,315 parts).The movements of anterior wall and posterior wall were synchronous.2.For all subjects,carotid Δt = 18.76 ± 5.80 s,femoral Δt = 23.53 ± 5.64 s,poplitealΔt = 30.16 ± 7.17 s,carotid Δt < femoral Δt < popliteal Δt(P < 0.017).3.There was no significant difference in carotid,femoral and popliteal Δt between patients and controls(P > 0.05).4.Carotid Δt was moderately related with systolic pressure,diastolic blood pressure,average blood pressure,weight and diameter of carotid artery(r = 0.457,0.485,0.534,0.454,0.403,all P < 0.05),and carotid Δt was weakly related with age(r=-0.309,P < 0.05)in the patient group.Femoral Δt was weakly related with height,weight and intima-media thickness of femoral artery(r = 0.264,0.343,0.326,all P <0.05)and popliteal Δt was weakly related with intima-media thickness of carotid artery(r =-0.309,P < 0.05)in healthy volunteers.【Conclusions】1.The arterial dilation occurs prior to the increase of blood velocity at the same location of artery.It seems that the arterial wall motion is not induced by the blood flow.2.Pulse waves propagate separately in vessel wall and flow,and there is timedifference between them.Pulse wave propagation in vessel wall is faster than that in flow.3.The time difference between the starting points of spectra of vessel wall and flow recorded by using dual pulsed-wave Doppler echocardiography was moderately related to blood pressure,which suggests further research of the relations between the time difference and blood pressure.4.The physiological mechanism of pulse wave propagation in vessel wall and flow deserves further investigation. |
