Effect Of Hypertension Duration On Atherosclerosis Of Carotid Or Cerebral Artery

Objective Combined transcranial doppler and carotid chromatic ultrasound to detect the carotid and cerebral atherosclerosis lesions in patients with hypertension, so as to explore the relevance between hypertension, duration and atherosclerosis, and to provide primary prevention evidences for hypertensive cerebrovascular events.Methods135patients with hypertension were collected and divided to3groups according to their duration, i.e.<5years,5-10yeas and>5years groups. On one hand, Using10MHz carotid chromatic ultrasound probe, bilateral common carotid artery(CCA), internal carotid artery(ICA) and extracranial part of external carotid artery(ECA) were detected. We measured the bilateral intima-medial thickness(IMT) of CCA on the place from carotid bifuracation1-2cm and recorded the amount, size and location of atheromatous plaques, as well as the characteristics and stenosis ratio. On the other hand, Using2MHz pulse doppler probe through bilateral temporal windows and pillow windows, the blood flow velocity(Vp、Vd、Vm), pulsatility index(PI), resistance index(RI) were recorded. Anterior cerebral artery(ACA) and middle cerebral artery(MCA) were regarded as the representative of the anterior circulation of intracranial artery, while basal artery(BA) and vertebral artery(VA)as that of the posterior circulation. In TCD spectrum, we selected the spectrum of a single-family cardiac cycle, identified the starting point(t0), the pulse-incisure point(ti), the end point(te) and the peak velocity point(tp), measured the time of the spectrum starting point to the peck velocity point(PT)and then calculated the time required of the peak velocity in the share of ventricular systolic(PTI-1)as well as the time required of the peak velocity point in the share of the whole cardiac cycle(PTI-2). Results(1) Carotid IMT of hypertension subgroups was significantly thickened compared with control group(P<0.05); carotid IMT of duration>10years subgroup was significantly thicker than that of5-10years subgroup; with the increase of duration, IMT became thicker, and there was a linear correlation between them(P<0.05).(2) The proportion of patients with carotid arterial atheromatous plaques in hypertension subgroups was significantly larger than that in control group(P<0.05); Meanwhile, the proportion in duration>10years subgroup was larger than that in duration<5years subgroup(P<0.05).(3) The plaques size scores between hypertension and control group were significantly different(P<0.05); there were significant differences among hypertension subgroups as well(P<0.05).(4) Carotid stenosis ratio of duration between5and10years and>10years subgroups was elevated compared with control group(P<0.05); compared with duration<5years subgroup, duration>10years subgroup had significantly increased carotid stenosis ratio(P<0.05).(5) The rate of abnormal TCD spectrum in hypertension group was significantly increased(P<0.05);the rate of BA and LMCA abnormal TCD spectrum in duration>10years subgroup was increased compared with that in duration<5years subgroup(P<0.05).(6) The PTI-1and PTI-2values in hypertension subgroups were higher than that in control group(P<0.05). The linear correlation analysis of PTI-1, PTI-2values and hypertension duration in BA, MCA showed that with the increase of duration, both values were elevated, and there was a linear correlation between them(P<0.05).(7) PI and RI values in duration>10years subgroup were increased compared with control group (P<0.05). PI and RI values in duration>10years subgroup were increased compared with duration<5years and between5and10years subgroups(P<0.05); the linear correlation analysis of PI, RI values and hypertension duration in BA and MCA showed that, with the duration increasing, PI and RI values were elevated, and there was a linear correlation between them(P<0.05).(8) Intracranial arterial stenosis rate of hypertension subgroups was increased compared with control group(P<0.01). Meanwhile, that of duration>10years subgroup was significantly higher than that of duration<5years subgroup(P<0.05).