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Endothelial Function and Cardiac Output in RV Pacing

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00508196
First Posted: July 27, 2007
Last Update Posted: October 12, 2017
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by:
University of Dundee
July 25, 2007
July 27, 2007
October 12, 2017
November 2006
Not Provided
endothelial function and cardiac output [ Time Frame: 30min to 1 week ]
Same as current
No Changes Posted
Not Provided
Not Provided
Not Provided
Not Provided
 
Endothelial Function and Cardiac Output in RV Pacing
Endothelial Function and Cardiac Output in Right Ventricular Pacing
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.

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.

Interventional
Not Provided
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: Double
Primary Purpose: Treatment
Bradycardia
  • Procedure: Dual chamber pacing with long AV delay
    for 1 week
  • Procedure: VVI pacing
    30 min
  • Experimental: A1
    Dual chamber pacing with long AV delay
    Intervention: Procedure: Dual chamber pacing with long AV delay
  • Experimental: A2
    Dual chamber pacing with long AV delay
    Intervention: Procedure: Dual chamber pacing with long AV delay
  • Experimental: A3
    VVI pacing
    Intervention: Procedure: VVI pacing
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Completed
22
July 2007
Not Provided

Inclusion Criteria:

  • Dual chamber pacemaker
  • Intact AV node function

Exclusion Criteria:

  • Unstable angina, heart failure
  • Inability to exercise
Sexes Eligible for Study: All
21 Years to 85 Years   (Adult, Senior)
No
Contact information is only displayed when the study is recruiting subjects
United Kingdom
 
 
NCT00508196
190906ver3
Yes
Not Provided
Not Provided
Not Provided
University of Dundee
Not Provided
Study Director: Allan Struthers, MD University of Dundee
University of Dundee
July 2007

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP