The Cyclocapnic Method for Measurement of Chemosensitivity

Heart Failure Clinical Trial

Official title:

Developing an Improved Measure of Chemosensitivity for the Study of Periodic Breathing in Heart Failure: the Cyclocapnic Method

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT01049256
• Other study ID #: 07/H0712/129
• Status: Recruiting
• Phase: Phase 1
• First received: January 13, 2010
• Last updated: January 13, 2010
• Start date: January 2008
• Est. completion date: October 2010

Study information

• Verified date: January 2010
• Source: Imperial College London
• Contact: Darrel P Francis, MD
• Phone: +44 207 594 1093
• Email: darrel.francis[@]imperial.ac.uk
• Is FDA regulated: No
• Health authority: UK: National research ethics committee
• Study type: Interventional

Clinical Trial Summary

We aim to test our method for measuring chemosensitivity (the ventilatory response to a change in carbon dioxide), which uses sinusoidal carbon dioxide stimuli.

Hypotheses:

• Carbon dioxide sensitivity is dependent on the cycle time over which we administer the gas (frequency).

• Chemoreflex gain decreases as deadspace increases.

Description:

We will apply a new method for the measurement of chemosensitivity (how sensitive a person is to changes in carbon dioxide), which is one of the principle determinants of whether people with heart failure develop abnormal breathing patterns We have shown in a pilot study that administering sinusoidal patterns of inspired carbon dioxide produces similar sinusoidal responses in ventilation. We aim to test our method for measuring chemosensitivity, which uses sinusoidal carbon dioxide stimuli (similar to those that drive the oscillations in ventilation found in periodic breathing). We aim to show that how the cycle time of carbon dioxide administered affects the resulting ventilatory oscillations and therefore that when measuring the chemoreflex clinically, it is important to deliver carbon dioxide stimuli that replicate the cycle time of oscillations in carbon dioxide seen in periodic breathing (typically approximately one minute).

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 45
• Est. completion date: October 2010
• Est. primary completion date: April 2010
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 18 Years to 80 Years

Eligibility

Inclusion Criteria:

• Heart failure subjects with stable cardiorespiratory control to be recruited from our institution's specialist heart failure clinic.

• Normal healthy volunteers, with normal systolic function.

Exclusion Criteria:

• We will exclude patients with chronic respiratory disease (every patient will have formal lung function testing on entrance into the study) or unstable coronary artery disease (myocardial infarction or unstable angina within the past 3 months).

• In addition any subjects receiving treatment with morphine and derivatives, theophylline, oxygen, benzodiazepines or acetazolamide will be excluded as these affect chemosensitivity.

Study Design

Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Heart Failure
• Periodic Breathing
• Respiratory Aspiration

Intervention

Other:
• carbon dioxide
sinusoidal carbon dioxide administration

Locations

Country	Name	City	State
United Kingdom	St Mary's Hospital	London

Sponsors (1)

Lead Sponsor	Collaborator
Imperial College London

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Chemoreflex gain as measured by cyclocapnic method		every minute	No