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Endothelial Function and Cardiac Output in RV Pacing

This study has been completed.
Information provided by:
University of Dundee Identifier:
First received: July 25, 2007
Last updated: July 26, 2007
Last verified: July 2007
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.

Condition Intervention
Bradycardia Procedure: Dual chamber pacing with long AV delay Procedure: VVI pacing

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: Double
Primary Purpose: Treatment
Official Title: Endothelial Function and Cardiac Output in Right Ventricular Pacing

Further study details as provided by University of Dundee:

Primary Outcome Measures:
  • endothelial function and cardiac output [ Time Frame: 30min to 1 week ]

Enrollment: 22
Study Start Date: November 2006
Study Completion Date: July 2007
Arms Assigned Interventions
Experimental: A1
Dual chamber pacing with long AV delay
Procedure: Dual chamber pacing with long AV delay
for 1 week
Experimental: A2
Dual chamber pacing with long AV delay
Procedure: Dual chamber pacing with long AV delay
for 1 week
Experimental: A3
VVI pacing
Procedure: VVI pacing
30 min

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.


Ages Eligible for Study:   21 Years to 85 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Dual chamber pacemaker
  • Intact AV node function

Exclusion Criteria:

  • Unstable angina, heart failure
  • Inability to exercise
  Contacts and Locations
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Please refer to this study by its identifier: NCT00508196

United Kingdom
Ninewells Hospital and medical School
Dundee, United Kingdom, DD1 9SY
Sponsors and Collaborators
University of Dundee
Study Director: Allan Struthers, MD University of Dundee
  More Information Identifier: NCT00508196     History of Changes
Other Study ID Numbers: 190906ver3
Study First Received: July 25, 2007
Last Updated: July 26, 2007

Keywords provided by University of Dundee:
right ventricular pacing
endothelial function
cardiac output

Additional relevant MeSH terms:
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes processed this record on September 20, 2017