The Efect On Hemodynamic Indexes In Middle-aged And Elderly Patients With Grade-1 Hypertension During One Time Incremental Exercise

Objective:To investigate the changing rules and influence factors of hemodynamic indexes during the incremental exercise of grade-1 hypertensive patients,and provide the different and appropriate exercise intensity guideline for different people.Method:According to the questionnaires and the testing of physiological indexes,biochemical indexes,55 participators in 45-60 age were recruited.The participators were separated into four groups: non-hypertension male group(OMN,n=15),grade-1 hypertension male group(OMH,n=12),non-hypertension female group(OFN,n=15),grade-1 hypertension female group(OFH,n=13).All participators used the horizontal power bike as the exercise model,used improved Bruce ramp scheme,the intensity was increased by target heart rate(THR)percentage(0%,20%,30%,40%,50%).Measured and recorded systolic blood pressure(SBP),diastolic blood pressure(DBP);hemodynamic indexes: wall shear stress(WSS),peak systolic velocity(PSV),resistance index(RI),pulse index(PI)and vascular inner diameter(ID);heart function indexes: stroke volume(SV),cardiac output(CO)in different phase: resting state,every HRR load,after exercising immediately,3 minutes after exercising,5 minutes after exercising.The electrocardiogram was used to monitor the motion synchronously.Results: In resting state,the WSS,PSV in hypertension groups were lower than those in non-hypertension groups(P<0.05),and the ID in OFH was higher than that in OFN(P<0.01).Hemodynamic indexes: with the increasing of exercise intensity,WSS,PSV showed an upward trend in four groups.The WSS in hypertension groups was significantly lower than WSS in non-hypertension groups(P<0.05)before the intensity reach to 50%THR;when the intensity arrived at 50%THR,comparing with 40%THR,WSS and PSV in non-hypertension groups increased slowly,there was no significant difference of WSS and PSV between different blood pressure groups.The ID decreased with the increase of intensity in all groups,OMN and OFN showed significantly difference decreasing(P<0.05).The PI and RI in four groups all decreased with the increasing of exercise load,then gradually recovered after exercising immediately.Cardiac function indexes: SV and CO increased with the increasing of exercise intensity.After the exercise stopped,the SV and CO kept decreasing.They had the same trend with WSS and PSV,there was no significant difference between different blood pressure groups.Correlation results: WSS was weakly positively correlated with SV(r=0.124);WSS was negatively correlated with ID(r=-0.556);WSS was moderately positively correlated with PSV(r=0.654).PSV was positively correlated with CO(r=0.304),and there was a weak positive correlation between blood flow velocity and SV(r=0.266),SV negatively correlated with ID(r=-0.216).Conclusions: 1.Compared with the non-hypertension groups,hypertensive people were characterized by low peak systolic velocity,low wall shear stress.2.Incremental exercise can increase peak systolic velocity through increasing stroke volume and cardiac output,then ultimately improve the level of wall shear stress of hypertension group,the systolic velocity was the most sensitive index which affecting the wall shear stress.3.From the perspective of hemodynamics,non-hypertension people in middle-aged and elderly can effectively increase the wall shear stress level when exercise intensity is 40%THR,while the most suitable exercise intensity for hypertension group is 50%THR.