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Estimation of Autonomic Nervous System Modulation by Pulse Plethysmographic Analysis

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01966198
Recruitment Status : Completed
First Posted : October 21, 2013
Last Update Posted : April 15, 2014
Information provided by (Responsible Party):
Riccardo Colombo, ASST Fatebenefratelli Sacco

Brief Summary:
Novel pulse plethysmography-derived indexes has been proposed as a tool to measure autonomic nervous system modulation in anaesthetized and awake patients, but nowadays a physiologic validation is lacking. We aim to examine the effects of sympathetic stimulation on pulse plethysmographic amplitude (PPGA), autonomic nervous system state (ANSS) and autonomic nervous system state index (ANSSi).

Condition or disease Intervention/treatment Phase
Autonomic Nervous System Modulation Other: Tilt test Not Applicable

Detailed Description:

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%.

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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

Arm Intervention/treatment
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.

Primary Outcome Measures :
  1. 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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Ages Eligible for Study:   25 Years to 35 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • adult healthy humans (american society of anesthesiologists class I)
  • age between 25 and 35 years old
  • no assumption of any drug, beverages containing caffeine or alcohol during the previous 24 hours
  • fasting 3 hours before the study protocol

Exclusion Criteria:

  • american society of anesthesiologists class >1
  • age <25 or >35 years
  • pregnancy
  • accidental discover of non sinus cardiac rhythm or ectopic beats >5%

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01966198

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Azienda Ospedaliera "Luigi Sacco" - Polo Universitario - University of Milan
Milan, Italy, 20157
Sponsors and Collaborators
ASST Fatebenefratelli Sacco


Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Riccardo Colombo, MD, ASST Fatebenefratelli Sacco Identifier: NCT01966198     History of Changes
Other Study ID Numbers: 31082013
First Posted: October 21, 2013    Key Record Dates
Last Update Posted: April 15, 2014
Last Verified: April 2014

Keywords provided by Riccardo Colombo, ASST Fatebenefratelli Sacco:
pulse plethysmography, autonomic nervous system, heart rate variability, baro-reflex