Effect of Posture on Left Ventricular (LV) Transvenous Lead Capture Thresholds (EXPECT)

This study has been terminated.
(Low enrollment rate than expected due to enrollment rate lower than expected and not expected to increase in the future)
Information provided by:
Baylor Research Institute
ClinicalTrials.gov Identifier:
First received: February 22, 2010
Last updated: January 26, 2012
Last verified: January 2012

The purpose of this study is to determine whether changes in a patient's position affect LV capture thresholds in a clinically significant way.

Condition Intervention
Congestive Heart Failure
Device: Medtronic 4195 active fixation LV lead and Medtronic passive fixation LV lead

Study Type: Interventional
Study Design: Intervention Model: Parallel Assignment
Masking: Open Label
Official Title: Effect of Posture on LV Transvenous Lead Capture Thresholds (EXPECT)

Resource links provided by NLM:

Further study details as provided by Baylor Research Institute:

Primary Outcome Measures:
  • Evidence of change in threshold of >1Volt with posture changes [ Time Frame: 6 months ] [ Designated as safety issue: No ]

Estimated Enrollment: 40
Study Start Date: December 2009
Estimated Study Completion Date: January 2012
Estimated Primary Completion Date: January 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 4195 VS Medtronic passive fixation LV lead
Medtronic 4195 Active Fixation LV lead and Medtronic passive fixation LV lead arms will both have same follow-up testing and schedule
Device: Medtronic 4195 active fixation LV lead and Medtronic passive fixation LV lead
1:1 randomization between Medtronic active fixation 4195 LV lead and another FDA approved passive fixation Medtronic LV lead. Fluoroscopic images will be taken at implant in a supine position and again at 3 month follow-up in different postural positions with capture thresholds of the LV lead taken at each postural position.

Detailed Description:

Traditionally clinicians program the safety margins for the right atrial, right ventricular, and left ventricular leads two-times the capture thresholds. This safety margin is necessary for the right atrial and right ventricular outputs to prevent asystole during fluctuation of capture thresholds. This two-times safety margin may not be necessary for the left ventricular lead output and may be causing shorter device battery longevity. Newly implemented LV capture threshold management algorithms may help maintain a proper balance of safety margin and battery longevity. However, recent research conducted on automatic left ventricular capture measurement (LVCM) shows as much as 3.5 V daily variability in capture thresholds. In this same study, 18% of patients had >1.5 V LV threshold variability. A possible explanation for the variability of LV thresholds is lead stability. Small movements of the lead electrodes associated with movement of patient posture may account for daily fluctuation of capture thresholds. As heart failure patient care and therapies improve, CRT patients may survive longer than the projected longevities of their device. In order to minimize patient risks associated with device change-outs, care must be taken to maximize battery longevity while maintaining CRT pacing. Examining patient posture changes as a possible cause of threshold variability may guide clinicians to program more appropriate LV outputs with patient safety and device longevity in mind.


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Greater than 18 years of age and able to provide informed consent
  • Planned placement of a Medtronic LV pacing lead and a Medtronic ICD generator with LVCM technology
  • Geographically stable and able to follow-up for a period of at least six months post-procedure at The Heart Hospital Baylor Plano
  • Willingness to comply with the requirements of the protocol

Exclusion Criteria:

  • Life expectancy of less than six months
  • Plans for or significant possibility of pregnancy during the required follow-up window
  • Significant cardiovascular surgery planned within six months following ICD implant
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01520714

United States, Texas
The Heart Hospital in Plano
Plano, Texas, United States, 75093
Sponsors and Collaborators
Baylor Research Institute
Principal Investigator: James B DeVille, M.D. Baylor Research Institute - The Heart Hospital Baylor Plano
  More Information

No publications provided

Responsible Party: J. Brian DeVille, M.D., The Baylor Heart Hospital at Plano
ClinicalTrials.gov Identifier: NCT01520714     History of Changes
Other Study ID Numbers: 009-067
Study First Received: February 22, 2010
Last Updated: January 26, 2012
Health Authority: United States: Institutional Review Board

Keywords provided by Baylor Research Institute:
Congestive Heart Failure (CHF)
Cardiac Resynchronization Therapy (CRT)
BiVentricular Implantable Cardioverter Defibrillator (BiVICD)

Additional relevant MeSH terms:
Heart Failure
Heart Diseases
Cardiovascular Diseases

ClinicalTrials.gov processed this record on April 15, 2014