Assessment Of Endothelial Function, Carotid Arterial Intima-media Thickness, The Left Ventricular Systolic And Diastolic Function In Patients With Early Essential Hypertension Using Ultrasound

ObjectiveEssential hypertension (EH), which caused by a variety of reasons to raise bloodpressure as the main manifestation of the disease. Vascular endothelial functioninvolved in the occurrence and development of hypertension, coronary heart disease,heart failure, and a series of cardiovascular disease. The carotid artery intima-mediathickness(IMT) is a good indicator to assess atherosclerosis. Using the high frequencyultrasound to measure vascular endothelial function and IMT to evaluate vascularendothelial dysfunction and the degree of atherosclerosis. Speckle tracking imaging(STI) is a new technique developed in recent years. There have a good prospect in theassessment of left ventricular systolic and diastolic function. In this study, by measuringthe changes of brachial artery diameter, IMT and left ventricular myocardial strain andstrain rate for normal control subjects and patients with early EH to evaluate thevascular endothelial function, the degree of carotid atherosclerosis and left ventricularsystolic and diastolic function, provided the basis prevention and treatment of essentialhypertension for clinical.MethodsThe study subjects include35patients with early EH and30normal controlsubjects.The brachial artery diameter at basic stage,the brachial artery diameter underreactive hyperemia condition, the brachial artery diameter response to nitroglycerin and the carotid arterial intima-media thickness were measured by high frequencyultrasonography of PHILIPS iU22. To analyse the correlation between the brachialartery endothelium dependent dilation and the carotid arterial intima-media thickness inpatients with early essential hypertension. Using GE Vivid7Dimension,probeM3S,frequency1.5~4.3MHz, The left ventricular diameter at end-diastole,the thicknessof interventricular septum and posterior wall were measured with echocardiographyfrom the parasternal Long-axis view. Left ventricular mass index (LVMI) wascalculated.Start Pulse-wave Doppler to measurem of mitral early diastolic peakvelocity(Ve), late diastolic peak velocity(Va), calculate the ratio(Ve/Va).The probe isplaced on the apex of the heart.The dynamic image of three consecutive cardiac cyclesof two-dimensional were collected from apical four-chamber, two-chamber and apicalleft ventricular long axis. Transport the dynamic image to the EchoPAC multi-parameteroff line analysis workstation. Basal,middle and apical segment of left ventricular wallpeak systolic longitudinal strain (SLs), strain rate (SrLs) and peak early diastolic strainrate (SrLe), peak late diastolic strain rate (SrLa) were measured by STI. And calculatethe average peak strain, strain rate(mSLs,mSrLs,mSrLe,mSrLa) and mSrLe/mSrLa.Results1. Comparison of high-frequency ultrasound measurements:There has significantdifference between the two groups in the brachial artery diameter at basic stage(P<0.05). The increased percentage of the brachial artery diameter under reactivehyperemia condition in patients with early EH decreased significantly comparedwith normal control group (P<0.01). There was no significant difference betweenthe early EH group and normal control group in response to nitroglycerin(P>0.05).The rate of the carotid atheromatous plaque have no significantly different fromcontrol group(P>0.05). The IMT in patients with early EH diagnosed incrassated significantly (P <0.05).2. Correlation analysis IMT and brachial artery FMD patients with early EH:Linearcorrelation analysis found that the flow-mediated dilation of brachial artery showeda significant negative correlation with the carotid arterial IMT in patients with earlyEH(r=-0.646,P <0.01).3. Comparison of general echocardiographic indices: The IVSTd and LVPwTd inpatients with early EH increased significantly (P <0.05). The LVEDd,LVMI,LVEFhave no significantly different from control group(P>0.05). The Ve and Ve/Va inpatients with early EH decreased significantly compared with normal controlsubjects (P <0.01). The Va in patients with early EH increased significantly(P<0.01).4. Comparison of SLs of the left ventricule walls using STI: Relative to the normalcontrol group, the middle and basal segments SLs of the left ventricule wallsdecreased in patients with early EH(P <0.01). Difference between the normalcontrol group and early EH group in the most apical segments SLs of the leftventricule walls have statistically significant (P <0.05).5. Comparison of SrLs of the left ventricule walls using STI: Compared with normalcontrol group,the basal segments SrLs of the left ventricule walls decreased inpatients with the early EH (P <0.01). The difference between two groups in themost middle segments SrLs of the left ventricule walls have statisticalsignificance(P <0.05). Difference between normal control group and early EHgroup in most apical segments SrLs of the left ventricule walls showed no statisticalsignificance (P>0.05).6. Comparison of SrLe and SrLa of the left ventricule walls using STI: All the SrLe ofthe left ventricule walls decreased significantly in patients with the early EH (P<0.05). The apical segments SrLa of the left ventricule walls increased in thepatient with EH and the normal control group(P <0.05). Difference between normal control group and early EH group in most middle and basal segments SrLaof the left ventricule walls in two group have no significant(P>0.05).7. Comparison of mSL and mSrL of the left ventricule walls using STI: Comparedwith normal control group, the mSLs and the mSrLs obviously decreased inpatients with early EH(P <0.01). The mSrLe and mSrLe/mSrLa in patients withearly EH decreased significantly compared to normal control group (P <0.01). Withrespect to normal control group, the mSrLa of the left ventricule walls increased inpatients with the early EH(P <0.01).Conclusion1. High-frequency ultrasound is a noninvasive, simple method to assess vascularendothelial function and the degree of arteriosclerosis for patients with early EH.2. Endothelium dependent dilation was impaired in patients with EH. The IMTincreased obviously compared with the normal control subjects. The endotheliumdependent dilation in patients with EH showed a significant negative correlationwith the IMT.3. STI have provides a new noninvasive method for detection the left ventricularsystolic and diastolic function for patients with EH.4. STI can be used for early diagnosis of left ventricular systolic dysfunction inpatients with EH.5. The left ventricular systolic and diastolic function destoryed in patients with earlyEH.