What happens to blood pressure when we stand up ?

Many times , an Innocuous question poses a real challenge, to our life time understanding of circulatory physiology. Submit a form. This question is very important , if we want to understand the true mechanism of postural hypotension, a commonest autonomic disorder in elderly (& also the newly recognised entity orthostatic hypertension) Orthostatic hypotension is defined as a sustained drop of at least 20 mm Hg in systolic blood pressure (SBP) or 10 mm Hg in diastolic blood pressure (DBP) within 3-5 minutes of going from a supine to a standing position. In patients with associated supine hypertension, the criteria for orthostatic hypotension allows for a drop of at least 30 mm Hg in SBP or 15 mm Hg in DBP. Mechanism Can you discuss the answer to the question please ? The correct answer is likely to be this. In normal adult, the systolic BP falls and diastolic BP is either static or raises by few mm . DBP is never expected to fall on standing, as the fall in systolic BP is invariable, that trigger a vasoconstriction which will increase the PVR and make sure the DBP doesn’t fall. In the process mean BP is kept near normal and regulated. However, hemodynamic response to standing has no fixed rules. That’s why we keep definitions, like acceptable fall in systolic and diastolic BP . It depends on , age , central and peripheral neurological nervous system, preconditioning of vascular tone.(Not only art...
Source: Dr.S.Venkatesan MD - Category: Cardiology Authors: Tags: Uncategorized bp response on standing hemodynamics of standing hypertesnion orthostatic hypertension orthostatic hypotension pots syndreome Source Type: blogs