What question did this study set out to answer?

To determine whether peripheral plasma renin responses to upright tilting differ between patients with orthostatic hypotension caused by afferent versus efferent autonomic lesions.

October 1, 1971Clinical Science

Plasma Renin in Idiopathic Orthostatic Hypotension: Differential Response in Subjects with Probable Afferent and Efferent Autonomic Failure

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Why the study?

Does head-up tilting induce different plasma renin concentration responses in patients with orthostatic hypotension due to afferent versus efferent autonomic failure?

Population

4 patients with orthostatic hypotension

Comparison

Head-up tilting vs Supine position and comparison between afferent…

Design

Case_series

Authors

DLDavid R. LoveFlinders University JBJ. J. BrownMRC Unit the Gambia RCR. H. ChinnChelsea and Westminster Hospital NHS Foundation Trust

Discussion

Member takes

Implication

Supports efferent sympathetic dependence for orthostatic renin release; hypothesis-generating for autonomic failure subtyping and requires prospective validation.

Key Points

To determine whether peripheral plasma renin responses to upright tilting differ between patients with orthostatic hypotension caused by afferent versus efferent autonomic lesions.
Measured peripheral venous plasma renin concentration (PRC) and blood pressure during head-up tilting and repeated tilting in four patients with orthostatic hypotension (N=4).
Evaluated autonomic function to classify patients into two groups: two patients with Holmes—Adie syndrome and afferent baroreceptor block, and two patients without the syndrome exhibiting efferent sympathetic pathway blocks.
Upright tilting induced a marked increase in PRC in patients with suspected afferent baroreceptor block, whereas no change in PRC occurred in patients with suspected efferent sympathetic block.
Repeated head-up tilting caused progressive increases in supine blood pressure and PRC in patients with afferent block, but induced no increase in either measure in patients with efferent block.

Structured PICO

Does head-up tilting induce different plasma renin concentration responses in patients with orthostatic hypotension due to afferent versus efferent autonomic failure?

Population

4 patients with orthostatic hypotension (2 with Holmes-Adie syndrome and suspected afferent block from baroreceptors, 2 with suspected interruption of efferent sympathetic pathways)

Intervention

Head-up tilting

Comparator

Supine position (baseline) and comparison between afferent vs. efferent block groups

Outcome

Changes in peripheral venous plasma renin concentration (PRC)surrogate

Renin release during orthostatic stress appears to depend on intact efferent sympathetic pathways but not necessarily on intact afferent baroreceptor reflexes.

Cite This Study

Love et al. (1971) studied this question.

synapsesocial.com/papers/6a851ecd76469a949f43cfdb https://doi.org/10.1042/cs0410289

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Implication

Supports efferent sympathetic dependence for orthostatic renin release; hypothesis-generating for autonomic failure subtyping and requires prospective validation.

Plasma Renin in Idiopathic Orthostatic Hypotension: Differential Response in Subjects with Probable Afferent and Efferent Autonomic Failure

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Plasma Renin in Idiopathic Orthostatic Hypotension: Differential Response in Subjects with Probable Afferent and Efferent Autonomic Failure

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider