Stimulus Intensity in Left Ventricular Leads (SILVeR-CRT)

This study has been completed.
Information provided by (Responsible Party):
Michael S. Lloyd, Emory University Identifier:
First received: January 29, 2010
Last updated: December 15, 2013
Last verified: December 2013
Cardiac resynchronization therapy (CRT) is a device implanted to improve the function of some people's hearts. CRT involves the placement of 3 wires in the heart through a vein near the front of your left or right shoulder into three pumping chambers of the heart, the most important being the left lower chamber, left ventricle (LV).

Condition Intervention
Congestive Heart Failure
Other: LV stimulus intensity

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Stimulus Intensity in Left Ventricular Leads and Response to Cardiac Resynchronization Therapy

Resource links provided by NLM:

Further study details as provided by Emory University:

Primary Outcome Measures:
  • Ejection Fraction [ Time Frame: 6 months ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Quality of Life [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • Six minute hall walk [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • End diastolic dimension [ Time Frame: 6 months ] [ Designated as safety issue: No ]

Enrollment: 60
Study Start Date: August 2008
Study Completion Date: February 2012
Primary Completion Date: June 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
LV lead low output

Low output on left ventricular pacing lead.

Intervention: LV stimulus intensity

Other: LV stimulus intensity

The voltage and pulse duration used for programmed LV pacing

Arm 1: LV lead low output Arm 2: LV lead high output

LV lead high output

High output on left ventricular lead

Intervention: LV stimulus intensity

Other: LV stimulus intensity

The voltage and pulse duration used for programmed LV pacing

Arm 1: LV lead low output Arm 2: LV lead high output

Detailed Description:
The purpose of Cardiac resynchronization therapy (CRT) is to send small amounts of energy (called pacing) through the wires to both the left and right lower chambers of your heart at (or near) the same time. This helps the heart pump in a more coordinated way and send more blood to your body with each beat. How much energy is used for pacing is called the stimulus intensity. Increasing the pacing stimulus intensity of the left ventricular wire can lead to an increase in the volume of heart muscle directly stimulated. This has previously been shown to produce beneficial effects on the heart function, like strength of contraction and increased volume of blood pumped. The purpose of this study is to determine if pacing the wires in the left ventricular chamber of the heart using higher stimulus intensity improves the strength of the heart's contraction.

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

Inclusion Criteria:

  • Adults who fulfill approved criteria to receive a cardiac resynchronization device.

Exclusion Criteria:

-Adults who are unable to give informed consent.

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01060449

United States, Georgia
Emory University Hospital
Atlanta, Georgia, United States, 30322
Sponsors and Collaborators
Emory University
Principal Investigator: Michael S. Lloyd, MD Emory University
  More Information

Responsible Party: Michael S. Lloyd, Principal Investigator, Emory University Identifier: NCT01060449     History of Changes
Other Study ID Numbers: IRB00016194  Medtronic-639130 
Study First Received: January 29, 2010
Last Updated: December 15, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by Emory University:
cardiac resynchronization therapy
congestive heart failure

Additional relevant MeSH terms:
Heart Failure
Cardiovascular Diseases
Heart Diseases processed this record on May 25, 2016