Endothelial Function and Cardiac Output in RV Pacing
Primary Purpose
Bradycardia
Status
Completed
Phase
Not Applicable
Locations
United Kingdom
Study Type
Interventional
Intervention
RVP-min
RVP-max
Sponsored by
About this trial
This is an interventional treatment trial for Bradycardia focused on measuring right ventricular pacing, endothelial function, cardiac output
Eligibility Criteria
Inclusion Criteria:
- Dual chamber pacemaker
- Intact AV node function
Exclusion Criteria:
- Unstable angina, heart failure
- Inability to exercise
Sites / Locations
- Ninewells Hospital and medical School
Outcomes
Primary Outcome Measures
Endothelial Function Assessed by Flow Mediated Vasodilatation
Flow mediated vasodilatation as measured by reactive hyperaemia peripheral arterial tonometry signal using EndoPAT software, Itamar.
A post-occlusion to pre-occlusion ratio is calculated by the EndoPAT software, providing the EndoPAT index (EnFI)
Secondary Outcome Measures
B-type Natriuretic Pepetide
Cardiac Output
measured at peak exercise on a standard exercise bicycle, measured non-invasively using the inert gas rebreathing technique (Innocor, Innovision A/S, Odense, Denmark).
Full Information
1. Study Identification
Unique Protocol Identification Number
NCT00508196
Brief Title
Endothelial Function and Cardiac Output in RV Pacing
Official Title
Endothelial Function and Cardiac Output in Right Ventricular Pacing
Study Type
Interventional
2. Study Status
Record Verification Date
March 2019
Overall Recruitment Status
Completed
Study Start Date
November 2006 (undefined)
Primary Completion Date
July 2007 (Actual)
Study Completion Date
July 2007 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Sponsor
Name of the Sponsor
University of Dundee
4. Oversight
Data Monitoring Committee
Yes
5. Study Description
Brief Summary
Pacing from the right ventricle (as is current practice in patients implanted with permanent pacemakers for bradycardia), has been associated with worse outcomes particularly in heart failure patients. Recent clinical trials suggest that chronic right ventricular pacing (VP) is associated with worsening heart failure, increased strokes and atrial fibrillation. Hemodynamically, right VP results in delayed activation and contraction of the LV which can give rise to functional mitral regurgitation, shortened diastolic filling time and thus reduced coronary filling, as well as abnormal arterial pulsatile flow. The mechanisms for the deleterious effects of right VP in heart failure patients have not been previously investigated. Our aim of this study is therefore to investigate the hemodynamic effects of right VP in stable heart failure patients in terms of exercise cardiac output (CO, an important measure of myocardial function and prognosis), as well as endothelial function which may be deranged as a result of abnormal arterial pulsatile flow.
Detailed Description
Study Aims The aim of this study is to investigate the effect of right ventricular pacing on CO at rest and exercise, and on endothelial function and B-type natriuretic peptide, BNP, in patients with heart failure.
Methods: Thirty patients with dual chamber pacemakers for sinus node disease will be recruited: 15 controls with normal LV function and 15 with stable impaired LV function (ejection fraction <40%). The pacemaker will be programmed to pace to back-up pacing at 55bpm in the atrial only (AAI, no right VP) for one week (baseline); and than programmed to overdrive pacing at 70-80bpm, randomised to either to dual chamber, DDD (sequential atrial and ventricular pacing) with a short AV delay (to ensure maximal right VP) or AAI (no RV pacing), for 1 week. There will be a crossover after a 1 week washout at backup AAI pacing at 55 bpm. Resting and exercise CO will be measured at the end of each pacing mode intervention using the Inocor system (a validated non invasive method of CO measurement, using inhaled inert gas equilibriums). Endothelial function will be measured non-invasively at the same time points, as will plasma BNP, a measure of LV strain. Patients with unstable heart failure or angina will be excluded.
Study Endpoints: Rest and exercise CO; and endothelial function and BNP with and without RV pacing, in patients with preserved and impaired LV function.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Bradycardia
Keywords
right ventricular pacing, endothelial function, cardiac output
7. Study Design
Primary Purpose
Treatment
Study Phase
Not Applicable
Interventional Study Model
Crossover Assignment
Masking
ParticipantInvestigator
Allocation
Randomized
Enrollment
22 (Actual)
8. Arms, Groups, and Interventions
Intervention Type
Other
Intervention Name(s)
RVP-min
Other Intervention Name(s)
DDD Long
Intervention Description
DDD pacing with long AV delay
Intervention Type
Other
Intervention Name(s)
RVP-max
Other Intervention Name(s)
DDD short
Intervention Description
DDD pacing with short AV delay
Primary Outcome Measure Information:
Title
Endothelial Function Assessed by Flow Mediated Vasodilatation
Description
Flow mediated vasodilatation as measured by reactive hyperaemia peripheral arterial tonometry signal using EndoPAT software, Itamar.
A post-occlusion to pre-occlusion ratio is calculated by the EndoPAT software, providing the EndoPAT index (EnFI)
Time Frame
1 week
Secondary Outcome Measure Information:
Title
B-type Natriuretic Pepetide
Time Frame
1 week
Title
Cardiac Output
Description
measured at peak exercise on a standard exercise bicycle, measured non-invasively using the inert gas rebreathing technique (Innocor, Innovision A/S, Odense, Denmark).
Time Frame
1 week
10. Eligibility
Sex
All
Minimum Age & Unit of Time
21 Years
Maximum Age & Unit of Time
85 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria:
Dual chamber pacemaker
Intact AV node function
Exclusion Criteria:
Unstable angina, heart failure
Inability to exercise
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Allan Struthers, MD
Organizational Affiliation
University of Dundee
Official's Role
Study Director
Facility Information:
Facility Name
Ninewells Hospital and medical School
City
Dundee
ZIP/Postal Code
DD1 9SY
Country
United Kingdom
12. IPD Sharing Statement
Plan to Share IPD
No
Learn more about this trial
Endothelial Function and Cardiac Output in RV Pacing
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