Skip to main content
  • American Heart Association
  • Science Volunteer
  • Warning Signs
  • Advanced Search
  • Donate

  • Home
  • About this Journal
    • Editorial Board
    • General Statistics
    • Circulation Doodle
      • Doodle Gallery
      • Circulation Cover Doodle
        • → Blip the Doodle
    • Information for Advertisers
    • Author Reprints
    • Commercial Reprints
    • Customer Service and Ordering Information
    • Subscribe to AHA Journals
  • All Issues
  • Subjects
    • All Subjects
    • Arrhythmia and Electrophysiology
    • Basic, Translational, and Clinical Research
    • Critical Care and Resuscitation
    • Epidemiology, Lifestyle, and Prevention
    • Genetics
    • Heart Failure and Cardiac Disease
    • Hypertension
    • Imaging and Diagnostic Testing
    • Intervention, Surgery, Transplantation
    • Quality and Outcomes
    • Stroke
    • Vascular Disease
  • Browse Features
    • AHA Guidelines and Statements
      • Recently Published Guidelines
    • Bridging Disciplines
    • → Articles Bridging Discplines
    • Go Red for Women Issue
    • Cardiovascular Case Series
    • Circulation at ESC
    • Circulation at AHA Scientific Sessions
    • Global Impact of the 2017 ACC/AHA Hypertension Guidelines
    • Circulation at ACC 2018
    • Circulation Supplements
    • ECG Challenge
    • Hospitals of History
      • Brigham and Women's Hospital
      • Hartford Hospital
      • Hospital Santa Maria del Popolo, Naples, Italy
      • Instituto do Coração-INCOR (São Paulo, Brasil)
      • Minneapolis City Hospital
      • Parkland Hospital: Dallas, Texas
      • Pennsylvania Hospital, Philadelphia
      • Pitié-Salpêtrière Hospital
      • Royal Infirmary of Edinburgh, Scotland
      • Tufts Medical Center
      • University of Michigan
      • Uppsala University Hospital
      • Vassar Brothers Medical Center (Poughkeepsie, NY)
      • Wroclaw Medical University
      • Women's College Hospital, Toronto, Canada
      • Henry Ford Hospital, Detroit, Michigan
      • Instituto Nacional de Cardiología Ignacio Chávez – INCICh México City, México
      • Kuang-Tien General Hospital (Taichug, Taiwan)
    • On My Mind
    • Podcast Archive
    • → Subscribe to Circulation on the Run
    • →Circulation FIT Podcast 2018
    • → #FITFAVs
  • Resources
    • Instructions for Authors
      • Accepted Manuscripts
      • Revised Manuscripts
    • → Article Types
    • → General Preparation Instructions
    • → Research Guidelines
    • → How to Submit a Manuscript
    • Journal Policies
    • Permissions and Rights Q&A
    • Submission Sites
    • Circulation CME
    • AHA Journals RSS Feeds
    • International Users
    • AHA Newsroom
  • AHA Journals
    • AHA Journals Home
    • Arteriosclerosis, Thrombosis, and Vascular Biology (ATVB)
    • Circulation
    • → Circ: Arrhythmia and Electrophysiology
    • → Circ: Genomic and Precision Medicine
    • → Circ: Cardiovascular Imaging
    • → Circ: Cardiovascular Interventions
    • → Circ: Cardiovascular Quality & Outcomes
    • → Circ: Heart Failure
    • Circulation Research
    • Hypertension
    • Stroke
    • Journal of the American Heart Association
  • Facebook
  • Twitter

  • My alerts
  • Sign In
  • Join

  • Advanced search

Header Publisher Menu

  • American Heart Association
  • Science Volunteer
  • Warning Signs
  • Advanced Search
  • Donate

Circulation

  • My alerts
  • Sign In
  • Join

  • Facebook
  • Twitter
  • Home
  • About this Journal
    • Editorial Board
    • General Statistics
    • Circulation Doodle
    • Information for Advertisers
    • Author Reprints
    • Commercial Reprints
    • Customer Service and Ordering Information
    • Subscribe to AHA Journals
  • All Issues
  • Subjects
    • All Subjects
    • Arrhythmia and Electrophysiology
    • Basic, Translational, and Clinical Research
    • Critical Care and Resuscitation
    • Epidemiology, Lifestyle, and Prevention
    • Genetics
    • Heart Failure and Cardiac Disease
    • Hypertension
    • Imaging and Diagnostic Testing
    • Intervention, Surgery, Transplantation
    • Quality and Outcomes
    • Stroke
    • Vascular Disease
  • Browse Features
    • AHA Guidelines and Statements
    • Bridging Disciplines
    • → Articles Bridging Discplines
    • Go Red for Women Issue
    • Cardiovascular Case Series
    • Circulation at ESC
    • Circulation at AHA Scientific Sessions
    • Global Impact of the 2017 ACC/AHA Hypertension Guidelines
    • Circulation at ACC 2018
    • Circulation Supplements
    • ECG Challenge
    • Hospitals of History
    • On My Mind
    • Podcast Archive
    • → Subscribe to Circulation on the Run
    • →Circulation FIT Podcast 2018
    • → #FITFAVs
  • Resources
    • Instructions for Authors
    • → Article Types
    • → General Preparation Instructions
    • → Research Guidelines
    • → How to Submit a Manuscript
    • Journal Policies
    • Permissions and Rights Q&A
    • Submission Sites
    • Circulation CME
    • AHA Journals RSS Feeds
    • International Users
    • AHA Newsroom
  • AHA Journals
    • AHA Journals Home
    • Arteriosclerosis, Thrombosis, and Vascular Biology (ATVB)
    • Circulation
    • → Circ: Arrhythmia and Electrophysiology
    • → Circ: Genomic and Precision Medicine
    • → Circ: Cardiovascular Imaging
    • → Circ: Cardiovascular Interventions
    • → Circ: Cardiovascular Quality & Outcomes
    • → Circ: Heart Failure
    • Circulation Research
    • Hypertension
    • Stroke
    • Journal of the American Heart Association
Original Article

Endogenous Circadian Rhythm in Vasovagal Response to Head-Up Tilt

Kun Hu, Frank A.J.L. Scheer, Michael Laker, Carolina Smales, Steven A. Shea
Download PDF
https://doi.org/10.1161/CIRCULATIONAHA.110.943019
Circulation. 2011;CIRCULATIONAHA.110.943019
Originally published February 21, 2011
Kun Hu
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Frank A.J.L. Scheer
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Michael Laker
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Carolina Smales
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Steven A. Shea
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • Article
  • Supplemental Materials
  • Info & Metrics
  • eLetters

Jump to

  • Article
  • Supplemental Materials
  • Info & Metrics
  • eLetters
Loading

Abstract

Background—The incidence of syncope exhibits a daily pattern with more occurrences in the morning, possibly as a result of influences from the endogenous circadian system and/or the daily pattern of behavioral/emotional stimuli. This study tested the hypothesis that the circadian system modulates cardiovascular responses to postural stress, leading to increased susceptibility to syncope at specific times of day.

Methods and Results—Twelve subjects underwent a 13-day in-laboratory protocol in which subjects' sleep-wake cycles were adjusted to 20 hours for 12 cycles. A 15-minute tilt-table test (60° head-up) was performed ≈4.5 hours after scheduled awakening in each cycle so that 12 tests in each subject were distributed evenly across the circadian cycle. Of 144 tests, signs/symptoms of presyncope were observed in 21 tests in 6 subjects. These presyncope events displayed a clear circadian rhythm (P=0.028) with almost all cases (17/21) occurring in the half of the circadian cycle corresponding to the biological night (10:30 pm to 10:30 am). Significant circadian rhythms were also observed in hemodynamic and autonomic function markers (blood pressure, heart rate, epinephrine, norepinephrine, and indices of cardiac vagal tone) that may underlie the circadian rhythm of presyncope susceptibility.

Conclusions—The circadian system affects cardiovascular responses to postural stress, resulting in greater susceptibility to presyncope during the night. This finding suggests that night-shift workers and people with disrupted sleep at night may have greater risk of syncope as a result of their exposure to postural stress during the biological night.

  • cardiovascular response
  • circadian rhythm
  • syncope
  • Received April 21, 2010.
  • Accepted January 5, 2011.
  • © 2011 American Heart Association, Inc.
Back to top
Next Article

Current Issue

Circulation
April 17, 2018, Volume 137, Issue 16
  • Table of Contents
Next Article

Jump to

  • Article
  • Supplemental Materials
  • Info & Metrics
  • eLetters

Article Tools

  • Print
  • Citation Tools
    Endogenous Circadian Rhythm in Vasovagal Response to Head-Up Tilt
    Kun Hu, Frank A.J.L. Scheer, Michael Laker, Carolina Smales and Steven A. Shea
    Circulation. 2011;CIRCULATIONAHA.110.943019, originally published February 21, 2011
    https://doi.org/10.1161/CIRCULATIONAHA.110.943019

    Citation Manager Formats

    • BibTeX
    • Bookends
    • EasyBib
    • EndNote (tagged)
    • EndNote 8 (xml)
    • Medlars
    • Mendeley
    • Papers
    • RefWorks Tagged
    • Ref Manager
    • RIS
    • Zotero
  • Article Alerts
    Log in to Email Alerts with your email address.
  • Save to my folders

Share this Article

  • Email

    Thank you for your interest in spreading the word on Circulation.

    NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.

    Enter multiple addresses on separate lines or separate them with commas.
    Endogenous Circadian Rhythm in Vasovagal Response to Head-Up Tilt
    (Your Name) has sent you a message from Circulation
    (Your Name) thought you would like to see the Circulation web site.
  • Share on Social Media
    Endogenous Circadian Rhythm in Vasovagal Response to Head-Up Tilt
    Kun Hu, Frank A.J.L. Scheer, Michael Laker, Carolina Smales and Steven A. Shea
    Circulation. 2011;CIRCULATIONAHA.110.943019, originally published February 21, 2011
    https://doi.org/10.1161/CIRCULATIONAHA.110.943019
    del.icio.us logo Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo

Related Articles

Cited By...

Subjects

  • Cardiology
    • Etiology
      • Arrhythmias, clinical electrophysiology, drugs
  • Arrhythmia and Electrophysiology
    • Electrophysiology
    • Arrhythmias

Circulation

  • About Circulation
  • Instructions for Authors
  • Circulation CME
  • Statements and Guidelines
  • Meeting Abstracts
  • Permissions
  • Journal Policies
  • Email Alerts
  • Open Access Information
  • AHA Journals RSS
  • AHA Newsroom

Editorial Office Address:
200 Fifth Avenue, Suite 1020
Waltham, MA 02451
email: circ@circulationjournal.org
 

Information for:
  • Advertisers
  • Subscribers
  • Subscriber Help
  • Institutions / Librarians
  • Institutional Subscriptions FAQ
  • International Users
American Heart Association Learn and Live
National Center
7272 Greenville Ave.
Dallas, TX 75231

Customer Service

  • 1-800-AHA-USA-1
  • 1-800-242-8721
  • Local Info
  • Contact Us

About Us

Our mission is to build healthier lives, free of cardiovascular diseases and stroke. That single purpose drives all we do. The need for our work is beyond question. Find Out More about the American Heart Association

  • Careers
  • SHOP
  • Latest Heart and Stroke News
  • AHA/ASA Media Newsroom

Our Sites

  • American Heart Association
  • American Stroke Association
  • For Professionals
  • More Sites

Take Action

  • Advocate
  • Donate
  • Planned Giving
  • Volunteer

Online Communities

  • AFib Support
  • Garden Community
  • Patient Support Network
  • Professional Online Network

Follow Us:

  • Follow Circulation on Twitter
  • Visit Circulation on Facebook
  • Follow Circulation on Google Plus
  • Follow Circulation on Instagram
  • Follow Circulation on Pinterest
  • Follow Circulation on YouTube
  • Rss Feeds
  • Privacy Policy
  • Copyright
  • Ethics Policy
  • Conflict of Interest Policy
  • Linking Policy
  • Diversity
  • Careers

©2018 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. The American Heart Association is a qualified 501(c)(3) tax-exempt organization.
*Red Dress™ DHHS, Go Red™ AHA; National Wear Red Day ® is a registered trademark.

  • PUTTING PATIENTS FIRST National Health Council Standards of Excellence Certification Program
  • BBB Accredited Charity
  • Comodo Secured