Estimation of Autonomic Nervous System Modulation by Pulse Plethysmographic Analysis
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|ClinicalTrials.gov Identifier: NCT01966198|
Recruitment Status : Completed
First Posted : October 21, 2013
Last Update Posted : April 15, 2014
|Condition or disease||Intervention/treatment||Phase|
|Autonomic Nervous System Modulation||Other: Tilt test||Not Applicable|
It has been supposed that indexes derived from pulse plethysmographic analysis -the autonomic nervous system state (ANSS) and ANSS index (ANSSi)- may be useful tools to measure the autonomic nervous system (ANS) activity but, to date, physiologic experimental evidences are lacking.
Traditionally,it is widely accepted that ANS modulation and the baro-reflex control can be non-invasively studied through heart rate variability (HRV) and systolic variability analyses.
The aim of this study is to assess if PPGA-derived indexes are able to detect changes of ANS system modulation directed to heart and vessels.
Changes in position of patients lead to changes in the balance of the ANS. One of the most used manoeuver to stimulate ANS is head-up tilt (HUT). Tilt causes pooling of blood toward lower body and reduces the venous return to the heart. These activation of ANS leads to an increase of heart rate and peripheral vascular resistance aiming to maintain arterial pressure near to the level preceding the challenge (baro-reflex control).
Methods: we study the effects of sympathetic stimulation on ANSS and ANSSi induced with two different tilt at 45 and 90 degrees angles. We compare the ANSS and ANSSi with HRV analysis and baro-reflex control analysis. We plan to study 7 volunteers to detect a difference of 30 (standard deviation of 15) between the mean of ANSS and ANSSi at baseline and during tilt, with a power of 80% and alfa error of 5%.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||10 participants|
|Intervention Model:||Single Group Assignment|
|Masking:||None (Open Label)|
|Primary Purpose:||Basic Science|
|Study Start Date :||October 2013|
|Actual Primary Completion Date :||October 2013|
|Actual Study Completion Date :||October 2013|
Experimental: all patients
Other: Tilt test
The experiment protocol consists of a sequence of passive postural changes gained with a tilt table, each of them lasting 10 minutes. The sequence consists of: (i) baseline recording in supine position; (ii) tilt at 45 degrees angle; (iii) recovery period in supine position; (iv) tilt at 90 degrees angle and (v) recovery in supine position.
- to measure the degree of correlation of ANSS and ANSSi with LF/HF and baroreflex sensitivity and their agreement in response to an orthostatic sympathetic load [ Time Frame: 1 week ]
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Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01966198
|Azienda Ospedaliera "Luigi Sacco" - Polo Universitario - University of Milan|
|Milan, Italy, 20157|