Postural Sway and Counterpressure Maneuvers for Pediatric Syncope

Summary

The investigators are interested in whether discrete counterpressure maneuvers, or muscle movements in the lower body, will boost blood pressure and cardiovascular control in children who faint. We will record cardiovascular responses to maneuvers of exaggerated sway, leg crossing, crouching, and gluteal muscle tensing in children who faint (N=20), as well as their height, weight, muscularity, and pubertal (Tanner) stage. Autonomic cardiovascular control will be measured using a Valsalva manoeuvre (expiration against a closed airway for 20 seconds) and a supine-stand test. The primary outcomes are noninvasive measures of cardiovascular responses to the maneuvers (blood pressure, cerebral blood flow, and stroke volume (volume of blood pumped per heartbeat). Comparisons will be made across levels of sex, diagnosis, Tanner stage, muscularity, height, and degree of autonomic control.

Conditions

• Syncope, Vasovagal
• Postural Orthostatic Tachycardia Syndrome
• Orthostatic Intolerance

Interventions

BEHAVIORAL

Counterpressure Maneuvers

Movements that can aid in delaying or preventing syncope by recruiting skeletal muscle pumping (via compression of major veins by contracting muscle to eject blood through cardiovascular circuit) and increased sympathetic drive (via sustaining an isometric muscle contraction). In this trial, we will be evaluating two clinically recommended isometric maneuvers (crouching, and leg crossing with muscle tensing) and two novel dynamic maneuvers that comprise discrete movement that the investigators have identified in prior work (exaggerated anterior-posterior postural sway, rhythmic gluteal clenching).

BEHAVIORAL

Baseline Stand

Participants will stand quietly for 5-minutes on a force platform to allow the investigators to assess their typical response to orthostasis.

Sponsors & Collaborators

• Provincial Health Services Authority British Columbia

  collaborator OTHER

• University of British Columbia

  collaborator OTHER

• Natural Sciences and Engineering Research Council, Canada

  collaborator OTHER

• Simon Fraser University

  lead OTHER

Principal Investigators

• Victoria E Claydon, PhD · Simon Fraser University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

6 Years

Max Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-04-17

Primary Completion

2027-05-31

Completion

2027-06-30

Countries

• Canada

Study Locations