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AV Delay Optimization vs. Intrinsic Conduction in Pacemaker Patients With Long PR Intervals (AV Delay)

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ClinicalTrials.gov Identifier: NCT02154750
Recruitment Status : Recruiting
First Posted : June 3, 2014
Last Update Posted : May 1, 2018
Sponsor:
Information provided by (Responsible Party):
Gregory Kent Feld, University of California, San Diego

Brief Summary:
This is a randomized, prospective clinical trial to determine the effects of two different pacemaker atrioventricular delay (AV delay) settings on heart function in patients with dual chamber pacemakers implanted for symptomatic bradycardia with long PR intervals (delayed conduction between upper and lower chambers of the heart). The study will compare a long, fixed AV delay (standard) with an optimized AV delay for each individual using echocardiography (experimental).

Condition or disease Intervention/treatment Phase
Atrioventricular Block Sick Sinus Syndrome Symptomatic Bradycardia Cardiac Arrhythmia Device: Long, fixed AV delay Device: Short, optimized AV delay Not Applicable

Detailed Description:

Cardiac pacing is the only effective treatment for symptomatic sinus node dysfunction. Most patients with preserved left ventricular function receive dual chamber pacemakers; however, right ventricular pacing can have detrimental effects on left ventricular function due to the abnormal electrical and mechanical activation pattern of the ventricles.

Many patients receiving dual chamber pacemakers for symptomatic bradycardia have prolonged intrinsic AV conduction (first degree AV block), and as a result, will receive a significant amount of ventricular pacing if programmed at physiologic AV intervals. As an alternative, many pacemakers can be programmed to minimize ventricular pacing at the expense of allowing longer AV delays. However, these long AV delays may not be physiologic and may also lead to reduced cardiac output. At present the standard of care is either to program the pacemaker at an physiologic "natural" AV delay of about 160 msec or to program the pacemaker with a long AV delay to minimize ventricular pacing.

The main scientific questions being addressed in this study are to evaluate the acute and chronic effects on cardiac output, functional status, sense of well-being, and cardiac remodeling of a long AV delay allowing for intrinsic conduction as compared to an echocardiographically optimized AV delay during dual chamber pacing.

Patients enrolled in the trial will complete a run-in period of two weeks prior to randomization in which pacemakers will be programmed with a long-fixed AV delay to allow intrinsic conduction and minimize ventricular pacing (standard). At two weeks, patients will receive a baseline echocardiogram. To determine optimal AV delay, all patients will undergo echocardiographic analysis at varying AV delays. Optimal AV delay will be defined as the AV delay associated with the largest average aortic Doppler velocity time integral (VTI). Then, patients will be randomized to either the short, optimized (experimental) or long, fixed (standard) AV delay groups. To assess functional status and sense of well-being, patients will complete a six minute walk test and Short Form-36 Medical Outcomes Study Questionnaire. Patients return to clinic for another study visit at 6 months and repeat research procedures, including baseline echocardiogram, questionnaire, and 6 minute walk test.


Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 50 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Participant)
Primary Purpose: Treatment
Official Title: Evaluation of AV Delay Optimization vs. Intrinsic Conduction in Patients With Long PR Intervals Receiving Dual Chamber Pacemakers for Symptomatic Bradycardia
Study Start Date : June 2013
Estimated Primary Completion Date : December 2018
Estimated Study Completion Date : December 2018

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
Active Comparator: Long, fixed AV delay
Pacemaker will be set to a long, fixed AV delay to minimize ventricular pacing
Device: Long, fixed AV delay
Pacemaker will be set to a long, fixed AV delay to minimize ventricular pacing

Experimental: Short, optimized AV delay
Pacemaker will be set to the AV delay that produces the greatest cardiac output in echocardiography for each patient enrolled
Device: Short, optimized AV delay
Pacemaker will be set to the AV delay that produces the greatest cardiac output in echocardiography for each patient enrolled.




Primary Outcome Measures :
  1. Change in cardiac output determined by echocardiography [ Time Frame: 6 months ]

Secondary Outcome Measures :
  1. Changes in functional status determined by 6 minute walk. [ Time Frame: 6 months ]
    Measure distance walked in 6 minutes in meters.

  2. Changes in sense of well being as determined by Short Form - 36 Medical Outcomes Study Questionnaire [ Time Frame: 6 months ]
    Sense of well being score determined by answers to questions on Short Form - 36 questionnaire.



Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Patient population: Individuals with 1st degree atrioventricular (AV) block who have received a dual chamber pacemaker for symptomatic bradycardia.

Inclusion Criteria:

  1. Patients greater than 18 years of age
  2. Patients with symptomatic sinus bradycardia
  3. Patients who meet standard indications for dual chamber pacemaker implantation
  4. Patients who have 1st degree AV block determined by PR interval > 200ms

Exclusion Criteria:

  1. Patients with complete or high grade AV block
  2. Patients who are unable to complete dual chamber pacemaker implantation for any reason
  3. Patients with congestive heart failure determined by a Left Ventricular Ejection Fraction < 45%
  4. Patients with persistent atrial fibrillation
  5. Sustained premature ventricular contractions (PVCs), premature atrial contractions (PACs), atrial flutter, or other heart conditions that may interfere with echocardiography measurements
  6. Patients who are pregnant
  7. Patients with Paroxysmal Atrial Fibrillation that have had an episode(s) within 30 days of consent

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02154750


Contacts
Contact: Maylene Alegre, BHS 858-246-2406 malegre@ucsd.edu

Locations
United States, California
UCSD Sulpizio Cardiovascular Center Recruiting
La Jolla, California, United States, 92093
Contact: Jessica A Hunter, BHS    858-246-2402    j2hunter@ucsd.edu   
Principal Investigator: Gregory K Feld, MD         
Sponsors and Collaborators
University of California, San Diego
Investigators
Principal Investigator: Gregory K Feld, MD UCSD Electrophysiology

Publications:
Responsible Party: Gregory Kent Feld, Professor of Medicine, University of California, San Diego
ClinicalTrials.gov Identifier: NCT02154750     History of Changes
Other Study ID Numbers: 130663
First Posted: June 3, 2014    Key Record Dates
Last Update Posted: May 1, 2018
Last Verified: April 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Keywords provided by Gregory Kent Feld, University of California, San Diego:
Sick Sinus Syndrome
Atrioventricular delay
AV delay
Pacemaker
Bradycardia
PR interval
Atrioventricular block
AV block
Echocardiography
Arrhythmia
AV optimization

Additional relevant MeSH terms:
Bradycardia
Arrhythmias, Cardiac
Sick Sinus Syndrome
Atrioventricular Block
Heart Diseases
Cardiovascular Diseases
Pathologic Processes
Arrhythmia, Sinus
Heart Block