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Chemoreflex Gain on Exercise

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified April 2010 by Imperial College London.
Recruitment status was:  Recruiting
Information provided by:
Imperial College London Identifier:
First received: January 13, 2010
Last updated: April 16, 2010
Last verified: April 2010
The purpose of this study is to assess chemoreflex gain on exercise.

Condition Intervention Phase
Exertional Periodic Breathing Other: carbon dioxide Phase 1

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Chemoreflex Gain on Exercise

Resource links provided by NLM:

Further study details as provided by Imperial College London:

Primary Outcome Measures:
  • chemoreflex gain on exercise [ Time Frame: every minute ]

Secondary Outcome Measures:
  • Reproducibility of chemoreflex gain on exercise [ Time Frame: every minute ]

Estimated Enrollment: 20
Study Start Date: February 2010
Estimated Study Completion Date: October 2010
Estimated Primary Completion Date: October 2010 (Final data collection date for primary outcome measure)
Intervention Details:
    Other: carbon dioxide
    sinusoidal carbon dioxide delivery
Detailed Description:

Normally breathing is controlled by a reflex that responds to the levels of carbon dioxide (CO2) in the blood. The change in breathing that results from a change in the blood's CO2 concentration is called the chemoreflex.

In heart failure, a condition where the heart muscle is damaged and can not pump as well, this reflex is exaggerated. The result of this can be breathing conditions characterised by patients hyperventilating at times and at other times taking very shallow breaths or even stopping altogether. In the past the only way of measuring this chemoreflex was to get patients to breathe into a large container and to rebreathe their exhaled air and allow the CO2 to rise over time, whilst keeping the oxygen constant. The proportion by which the ventilation increases with increasing carbon dioxide is the chemoreflex gain. Unfortunately, because this test takes a long time to conduct, requires specialist knowledge and equipment it has not been possible to measure this reflex on exercise.


Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Volunteers: Males aged 18-80 years who are able to perform both running and cycling and can follow simple visual instructions.
  • Heart Failure Subjects: Males aged 18-80 with a clinical diagnosis of heart failure who are able to perform both running and cycling and can follow simple visual instructions.

Exclusion Criteria:

  • Chest pain of any cause within 4-6 days,
  • Pulmonary oedema,
  • Uncontrolled hypertension (systolic blood pressure > 220 mm Hg, diastolic >120 mm Hg),
  • Severe aortic stenosis,
  • Severe hypertrophic obstructive cardiomyopathy,
  • Untreated life threatening arrhythmia,
  • Dissecting aneurysm,
  • Recent surgery (within 4-6 weeks), COPD.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01050179

Contact: Darrel P Francis, MD +44 207 594 1093

United Kingdom
St Mary's Hospital Recruiting
Paddington, London, United Kingdom, W2 1LA
Contact: Resham Baruah, MBBS    02075941027   
Principal Investigator: Darrel P Francis, MD         
Sponsors and Collaborators
Imperial College London
  More Information

Responsible Party: Darrel Francis, Imperial College Identifier: NCT01050179     History of Changes
Other Study ID Numbers: 10/H0712/9
Study First Received: January 13, 2010
Last Updated: April 16, 2010

Keywords provided by Imperial College London:
chemosensitivity processed this record on September 21, 2017