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Atrioventricular BlockAV DelayNCT02154750

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

A study testing Long, fixed AV delay and Short, optimized AV delay in people with Atrioventricular Block and Sick Sinus Syndrome, run by University of California, San Diego at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial 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… Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
Long, fixed AV delay and Short, optimized AV delay
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
23 participants
Where
1 siteUnited States
Study dates
1 Jun 2013to 31 Dec 2021
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

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

Who cannot join

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

Trial locations and contacts

1 site in 1 country.

United States1 site
  • UCSD Sulpizio Cardiovascular Center

    La Jolla, California, 92093

Other trials in United States

About this study

Official title: Evaluation of AV Delay Optimization vs. Intrinsic Conduction in Patients With Long PR Intervals Receiving Dual Chamber Pacemakers for Symptomatic Bradycardia

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).

Read the 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.

Being tested
Long, fixed AV delay, Short, optimized AV delay
Keywords
Atrioventricular delay, AV delay, Pacemaker, Sick Sinus Syndrome, Bradycardia, PR interval, Atrioventricular block, AV block, Echocardiography, Arrhythmia, AV optimization
Medical subject headings
Atrioventricular Block, Sick Sinus Syndrome, Arrhythmias, Cardiac, Bradycardia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Long, fixed AV delayDevice

    Pacemaker will be set to a long, fixed AV delay to minimize ventricular pacing

  • Short, optimized AV delayDevice

    Pacemaker will be set to the AV delay that produces the greatest cardiac output in echocardiography for each patient enrolled.

Study groups in NCT02154750
Study groupRoleWhat they receive
Long, fixed AV delayActive comparatorPacemaker will be set to a long, fixed AV delay to minimize ventricular pacing
Receives: Device: Long, fixed AV delay
Short, optimized AV delayExperimentalPacemaker will be set to the AV delay that produces the greatest cardiac output in echocardiography for each patient enrolled
Receives: Device: Short, optimized AV delay

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Comparison of Change in Echocardiographic Parameters LV Dimension at End-diastole, LV Dimension at End-systole, and Tricuspid Annular Plane Systolic Excursion (cm) From Baseline to Followup, in Optimized AV Delay Versus Long-fixed AV Delay Groups.

    Comparison (∆) of change in echocardiographic parameters left ventricular (LV) dimension at end-diastole, left ventricular (LV) dimension at end-systole, and tricuspid annular plane systolic excursion (cm) from baseline to followup, in Optimized AV delay versus Long-fixed AV delay groups. A reduction LV dimension indicates improvement in function, and an increase in tricuspid annular plane excursion represents an improvement in function.

    Measured: 6 months

  2. Comparison of Echocardiographic Parameters Mitral E Wave Velocity (cm/s) and Mitral A Wave Velocity (cm/s) at Baseline and Followup, in Optimized AV Delay Versus Long-fixed AV Delay Group.

    Comparison (∆) of echocardiographic parameters mitral E wave velocity (cm/s) and mitral A wave velocity (cm/s) at baseline and followup, in Optimized AV delay versus Long-fixed AV delay group. An increase in mitral E wave velocity and a decrease in mitral A velocity represent an improvement in function.

    Measured: 6 months

  3. Comparison of Change in Echocardiographic Parameter ΔE/A and Mean E/e' Ratio (Unitless) From Baseline to Followup, in Optimized AV Delay Versus Long-fixed AV Delay Groups.

    Comparison (Δ) of change in echocardiographic parameter ΔE/A and Mean E/e' ratio (unitless) from baseline to followup, in Optimized AV delay versus Long-fixed AV delay groups. An higher delta E/A and mean E/e' ratio represent improvement in function,

    Measured: 6 months

  4. Comparison of Echocardiographic Parameter Deceleration Time (Msec) at Baseline and Followup, in Optimized AV Delay Versus Long-fixed AV Delay Group.

    Comparison (∆) of Echocardiographic Parameter Deceleration time (msec) at Baseline and Followup, in Optimized AV Delay Versus Long-fixed AV Delay Group. A reduction in deceleration time represents an improvement in function.

    Measured: 6 months

  5. Comparison of Change in Echocardiographic Parameters LVED End Diastolic Volume Index, LVES Volume Index, Maximum LA Volume Index, and Minimum LA Volume Index (ml/m2) From Baseline to Follow-up, in Optimized AV Delay Versus Long-fixed AV Delay Groups.

    Comparison of change in echocardiographic parameters left ventricular end diastolic (LVED) volume index, left ventricular end systolic (LVES) volume index, maximum left atrial (LA) volume index, and minimum left atrial (LA) volume index (ml/m2) from baseline to follow-up, in Optimized AV delay versus Long-fixed AV delay groups. A reduction in volume indexes represents an improvement in function.

    Measured: 6 months

  6. Comparison of Change in Echocardiographic Parameters Left Ventricular Ejection Fraction and Global Longitudinal Strain (%) From Baseline to Followup, in Optimized AV Delay Versus Long-fixed AV Delay Groups.

    Comparison (∆) of Change in Echocardiographic Parameters Left Ventricular Ejection Fraction and Global Longitudinal Strain (%) From Baseline to Followup, in Optimized AV Delay Versus Long-fixed AV Delay Groups. An increase in left ventricular ejection time represents an improvement in function. A more negative global longitudinal strain % represents an improvement in function.

    Measured: 6 months

  7. Comparison of Change in Echocardiographic Parameters Tricuspid Regurgitation (TR) Velocity m/s From Baseline to Followup, in Optimized AV Delay Versus Long-fixed AV Delay Groups.

    Comparison (∆) of Change in Echocardiographic Parameters Tricuspid Regurgitation (TR) velocity m/s From Baseline to Followup, in Optimized AV Delay Versus Long-fixed AV Delay Groups. An reduction in tricuspid regurgitation velocity represents an improvement in function.

    Measured: 6 months

  8. Comparison of Change in Echocardiographic Parameters Left Ventricular Mass (gm) From Baseline to Followup, in Optimized AV Delay Versus Long-fixed AV Delay Groups.

    Comparison (∆) of Change in Echocardiographic Parameters left ventricular mass (gm) From Baseline to Followup, in Optimized AV Delay Versus Long-fixed AV Delay Groups. A reduction in left ventricular mass represents an improvement in function.

    Measured: 6 months

Secondary outcomes (1)
  1. Comparison of Measured Distance Walked in 6 Minutes in Meters From Baseline and Followup, in Optimized AV Delay Group Versus Long-fixed AV Delay Group.

    Comparison (∆) of measured distance walked in 6 minutes in meters from baseline and followup, in Optimized AV delay group versus Long-fixed AV delay group. An increase in distance walked during the 6 minute walk test represents an improvement in function.

    Measured: 6 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted3 Jun 2014 (estimated)
  2. Study start1 Jun 2013
  3. Primary completion31 Dec 2021
  4. Study completion31 Dec 2021

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Participant
Enrolment
23 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02154750
Sponsor's protocol ID
130663
Acronym
AV Delay
Status last verified
Jul 2025
First submitted
28 May 2014
Last updated
24 Jul 2025
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
Yes
Individual data sharing
No

Publications

  • Sawhney NS, Waggoner AD, Garhwal S, Chawla MK, Osborn J, Faddis MN. Randomized prospective trial of atrioventricular delay programming for cardiac resynchronization therapy. Heart Rhythm. 2004 Nov;1(5):562-7. doi: 10.1016/j.hrthm.2004.07.006.

    PubMed 15851220
  • Tops LF, Schalij MJ, Bax JJ. The effects of right ventricular apical pacing on ventricular function and dyssynchrony implications for therapy. J Am Coll Cardiol. 2009 Aug 25;54(9):764-76. doi: 10.1016/j.jacc.2009.06.006.

    PubMed 19695453
  • Iliev II, Yamachika S, Muta K, Hayano M, Ishimatsu T, Nakao K, Komiya N, Hirata T, Ueyama C, Yano K. Preserving normal ventricular activation versus atrioventricular delay optimization during pacing: the role of intrinsic atrioventricular conduction and pacing rate. Pacing Clin Electrophysiol. 2000 Jan;23(1):74-83. doi: 10.1111/j.1540-8159.2000.tb00652.x.

    PubMed 10666756
  • Sweeney MO, Ellenbogen KA, Tang AS, Whellan D, Mortensen PT, Giraldi F, Sandler DA, Sherfesee L, Sheldon T; Managed Ventricular Pacing Versus VVI 40 Pacing Trial Investigators. Atrial pacing or ventricular backup-only pacing in implantable cardioverter-defibrillator patients. Heart Rhythm. 2010 Nov;7(11):1552-60. doi: 10.1016/j.hrthm.2010.05.038. Epub 2010 Jun 4.

    PubMed 20685401

Questions about this trial

What is this clinical trial studying?

A study testing Long, fixed AV delay and Short, optimized AV delay in people with Atrioventricular Block and Sick Sinus Syndrome, run by University of California, San Diego at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 24 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 12 Jun 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Comparison of Change in Echocardiographic Parameters LV Dimension at End-diastole, LV Dimension at End-systole, and Tricuspid Annular Plane Systolic Excursion (cm) From Baseline to Followup, in Optimized AV Delay Versus Long-fixed AV Delay Groups. (time frame: 6 months). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02154750, which also lists 4 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Jul 2025.

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