N/A
N=23
AV Delay Optimization vs. Intrinsic Conduction in Pacemaker Patients With Long PR Intervals
Atrioventricular Block · Sick Sinus Syndrome · Symptomatic Bradycardia · Cardiac Arrhythmia
Bottom Line
View on ClinicalTrials.gov: NCT02154750 ↗Enrolled (actual)
23
Serious AEs
0.0%
Results posted
Jun 2025
Primary outcome: Primary: 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. — -3.1; 0.1; -4.2; -1.9 cm
Study Design & Population
- Study type
- Interventional
- Phase
- N/A
- Interventions
- Long, fixed AV delay (Device); Short, optimized AV delay (Device)
- Age
- Adult, Older Adult · 18+ yrs
- Sex
- All
- Sponsor
- University of California, San Diego
- Primary completion
- Dec 2021
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY 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. |
-3.1; 0.1; -4.2; -1.9; 2.4; 2.3 | — |
| PRIMARY 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. |
-5.5; 0.8; 3.5; 0.0 | — |
| PRIMARY 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. |
5.8; -15.9; -1.1; -5.6 | — |
| PRIMARY Comparison of Echocardiographic Parameter Deceleration Time (Msec) at Baseline and Followup, in Optimized AV Delay Versus Long-fixed AV Delay Group. |
14.6; 2.1 | — |
| PRIMARY 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. |
-13.2; 5.8; -16.4; 6.7; -9.7; 0.6 | — |
| PRIMARY 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. |
4.4; -0.7; 5.5; -11.8 | — |
| PRIMARY 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. |
2.2; 2.2 | — |
| PRIMARY Comparison of Change in Echocardiographic Parameters Left Ventricular Mass (gm) From Baseline to Followup, in Optimized AV Delay Versus Long-fixed AV Delay Groups. |
142.8; 148.4 | — |
| SECONDARY 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. |
368.7; 473.8 | — |
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).
Eligibility Criteria
Patient population: Individuals with 1st degree atrioventricular (AV) block who have received a dual chamber pacemaker for symptomatic bradycardia.
Inclusion Criteria
- 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
Exclusion Criteria
- 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
Data sourced from ClinicalTrials.gov (NCT02154750). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.