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Abstract:This study was carried out on 21 normal healthy male volunteers, aged 20-40 years inorder to study cardiovascular reflexes response to postural changes at rest and duringexercise by using non-invasive technique. Bicycle ergo-meter for doing…
Abstract:This study was carried out on 21 normal healthy male volunteers, aged 20-40 years inorder to study cardiovascular reflexes response to postural changes at rest and duringexercise by using non-invasive technique. Bicycle ergo-meter for doing exercise, mercurysphygmomanometer for measuring the blood pressure(BP) and Dopplerechocardiography for estimating of heart rate(HR), stroke volume(SV), cardiacoutput(CO), velocity time integral(VTI), ejection time(ET), peak or maximum flowvelocity through aortic valve(Vmx) and maximum pressure gradient across aorticvalve(PGmx). The results were at rest there are significant increase in HR, diastolic BP,mean BP, peripheral vascular resistance(PVR) and significant decrease in SV, CO, VTI,ET in upright position on comparison with the supine position, while systolic BP, Vmx,PGmx are not significantly different between both positions at rest.During change from rest to exercise all variables significantly changed in bothpositions except ET during upright exercise which is not significantly decreased.On comparison between supine and upright exercise it was found that there aresignificantly higher HR, systolic BP, PVR and significantly lower SV, CO, VTI inupright exercise in comparison with supine exercise, while diastolic BP, mean BP, ET,Vmx, PGmx are not significantly different between supine and upright exercise.On comparison between the differences in both positions in response to exercise it wasfound that there are significantly higher HR, systolic BP, PVR and significantly lowerCO, diastolic BP, ET in upright position on comparison with the supine position, whilemean BP, VTI, Vmx, PGmx not significantly changed.We concluded that there is inverse relationship between HR and ET and directrelationship between VTI and Vmx.
