Related Experiment Video
Updated: Apr 4, 2026
Measuring Cardiac Autonomic Nervous System ANS Activity in Children
Published on: April 29, 2013
A Novel Noninvasive Device to Assess Sympathetic Nervous System Function in Patients With Heart Failure
Monica Parry1, Chantelle A Nielson, Fiona Muckle
1Monica Parry, NP-Adult, PhD, CCN(C), is Assistant Professor and Director, Lawrence S. Bloomberg Faculty of Nursing, University of Toronto, and is Nurse Practitioner, Cardiac Program, Kingston General Hospital, Ontario, Canada. Chantelle A. Nielson, MSc, is Undergraduate Nursing Student; and Fiona Muckle, MSc, is Registered Nurse, Lawrence S. Bloomberg Faculty of Nursing, University of Toronto, Ontario, Canada. Sheila O'Keefe-McCarthy, PhD, is Adjunct Scientist, Ross Memorial Hospital, Lindsay, Ontario, Canada. Rene van Lien, PhD, is Product Specialist, Heinen and Lowenstein, Rotterdam, the Netherlands. Jan H. Meijer, PhD, is Biomedical Physicist, Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, the Netherlands.
Background:
Heart failure is a complex syndrome associated with sympathetic nervous system and renin-angiotensin-aldosterone system hyperactivity. Sympathoinhibition and downregulation of sympathetic activity using medications and exercise training improve outcomes in patients with heart failure. Impedance cardiography provides data on hemodynamic and autonomic function that may assist with safe medication, exercise monitoring, and titration.
Purpose:
The purpose of this pilot study was to evaluate the sensitivity of the Vrije Universiteit Ambulatory Monitoring System (VU-AMS) version 5fs to detect hemodynamic and sympathetic nervous system changes associated with postural shift in persons with heart failure with reduced ejection fraction.
Methods:
In this descriptive study, participants (N = 28) were recruited from an outpatient device clinic at a tertiary care hospital in Ontario, Canada. They completed a sit-to-stand posture protocol wearing an ambulatory blood pressure (ABP) and a noninvasive VU-AMS version 5fs impedance cardiography system.
Results:
Most (n = 18, 64%) participants were eliminated from the final analyses in this sample because of difficulty in Q-onset and B-point identification in peculiar electrocardiogram and impedance cardiogram waveforms. The remaining participants (n = 10) had a mean age of 69 years (SD = 10 years) and responses to a sit-to-stand posture protocol that included a 5% increase in heart rate (p = .001), an 18% decrease in stroke volume (p = .01), and an 8% decrease in left ventricular ejection time (p = .01). Participants had an increased preejection period (11%, p = .01), a drop in cardiac output of 13% (p = .02), and a reduced mean arterial pressure of approximately 4% (p = .09) with standing.
Discussion:
Although the VU-AMS version 5fs system detected anticipated hemodynamic and sympathetic nervous system changes to postural shift in participants (n = 10), the elimination of 64% (n = 18) of the sample because of scoring difficulties limits the use of this impedance cardiography device using standard scoring algorithms in persons with heart failure with reduced ejection fraction.
More Related Videos
07:49Author Spotlight: Investigating HR-Dependent Cardiac Function in Mouse Models Through a Novel Atrial-Pacing Approach
Published on: July 21, 2023
04:20Integration of Brain Tissue Saturation Monitoring in Cardiopulmonary Exercise Testing in Patients with Heart Failure
Published on: October 1, 2019
Related Concept Videos
01:29Heart Failure II: Pathophysiology
01:26Heart Failure Drugs: Inhibitors of Renin-Angiotensin System
01:26Exercise Stress Test
Exercise stress testing, commonly known as a treadmill test, is a noninvasive procedure used to evaluate cardiovascular function and diagnose heart conditions.
Definition
An exercise stress test measures the heart's response to exertion using a treadmill or stationary bicycle. Chest electrodes record the heart's electrical activity through an ECG, and blood pressure is monitored regularly.
Purposes
01:31Regulation of Heart Rates
The SNS increases heart rate through the release of norepinephrine and epinephrine, which act on beta-1 adrenergic receptors in the heart. This action increases the rate of depolarization in the sinoatrial (SA) node, the heart's...
01:22Heart Failure Drugs: β-Blockers
01:27Assessment of the Cardiovascular System III: Palpation
Jugular Venous Pressure (JVP) Measurement
Position the patient at a thirty- to forty-five-degree angle or in a semi-fowler's position. Look for the highest point of pulsation in the internal jugular vein and measure the vertical distance to the angle of Loius or sternal angle. A normal JVP is 3-4 cm above...