Optimal Coronary Sinus Lead Implantation Using Intracardiac Impedography and Magnetic Resonance Imaging

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01129635
Recruitment Status : Completed
First Posted : May 24, 2010
Last Update Posted : January 21, 2015
Information provided by (Responsible Party):
Michael S. Lloyd, Emory University

Brief Summary:
Despite the dramatic effect of cardiac resynchronization therapy (CRT) on survival and morbidity in people with congestive heart failure, 50-70% of eligible patients do not respond to this intervention. There is retrospective evidence that placement of the left ventricular (LV) lead at the region of latest mechanical delay markedly improves response to CRT. However, there is no feasible way to gauge dyssynchrony at LV lead sites during CRT implantation. Impedance recordings from pacing lead tips allow for real-time assessment of mechanical motion and may represent a useful intraoperative tool to guide optimum placement of the LV lead during CRT implantation. This pilot trial will assess the use of intraoperative impedograms in humans to measure regional dyssynchrony at potential LV lead locations during CRT implantation.

Condition or disease Intervention/treatment Phase
Heart Failure, Systolic Left Bundle Branch Block Procedure: Cardiac Resynchronization Therapy (CRT) implantation Not Applicable

Detailed Description:

This is a clinical trial using intracardiac impedance signals (impedograms) to assess regional dyssynchrony at various sites of left ventricular (LV) lead placement in humans undergoing CRT device implantation. This study will test the following hypotheses during the funding period:

  1. LV lead impedograms as an implant tool to place leads at sites of latest mechanical delay are feasible and correlate with other means of assessing dyssynchrony.
  2. LV lead impedograms vary significantly depending on LV lead location.
  3. There are several characteristics of LV lead impedograms that correlate with mechanical phenomena of the heart.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 38 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Real-Time Intracardiac Impedograms of Left Ventricular Leads to Locate Sites of Latest Mechanical Delay in Cardiac Resynchronization Therapy
Study Start Date : June 2010
Actual Primary Completion Date : August 2014
Actual Study Completion Date : December 2014

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Heart Failure

Arm Intervention/treatment
Experimental: CRT Candidate

Patients with NYHA Class III or IV heart failure; EF ≤ 30% and QRS duration ≥ 120 ms, who are scheduled for CRT surgery.

Intervention: Cardiac Resynchronization Therapy (CRT) implantation

Procedure: Cardiac Resynchronization Therapy (CRT) implantation

The impedance measurement is performed during device implantation following CMR. After the RV and LV leads are inserted, secured and tested, they will be connected to the impedance monitor. Impedance recording of at least ten beats will be acquired and stored for future analysis. Each recording will be tagged with the anatomical location of the LV lead. Subsequently, the LV lead will be moved to a different location and the same procedure will be repeated until accessible coronary sinus sites are exhausted. The ultimate LV lead location is determined by the implanting electrophysiologist and is not constrained by the study protocol. Finally, the LV lead will be tested again and the rest of the implantation procedure will proceed as routine.

Arm: CRT Candidate

Primary Outcome Measures :
  1. Anatomic correlation between largest Ts (see description) and site of longest delay among probed locations in the CMR dyssynchrony map. [ Time Frame: Acute intraoperative measurement ]

    Parameter will be recorded for at least 10 consecutive heartbeats during sinus and RV paced rhythm

    Ts = The average time from the sensed RV IEGM to the peak of the LV impedance curve

Secondary Outcome Measures :
  1. Differential correlation of Ts, Tp, and Td (see description) to the CMR dyssynchrony map. [ Time Frame: Acute intraoperative measurement ]

    Ts: The average time from the sensed RV IEGM to the peak of the LV impedance curve.

    Tp: The average time from the paced RV IEGM to the peak of the LV impedance curve.

    Td: The difference between Ts and Tp (Tp - Ts).

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients with NYHA class III or IV heart failure
  • LVEF ≤ 30%
  • QRS duration ≥ 120 ms

Exclusion Criteria:

  • Not a candidate for CRT implantation

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 identifier (NCT number): NCT01129635

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


Responsible Party: Michael S. Lloyd, PI, Emory University Identifier: NCT01129635     History of Changes
Other Study ID Numbers: IRB00036655
ACTSI-EP-001 ( Other Identifier: Other )
First Posted: May 24, 2010    Key Record Dates
Last Update Posted: January 21, 2015
Last Verified: January 2015

Keywords provided by Michael S. Lloyd, Emory University:
Heart failure
Cardiac resynchronization therapy
Regional left ventricular dyssynchrony

Additional relevant MeSH terms:
Heart Failure
Bundle-Branch Block
Heart Failure, Systolic
Heart Diseases
Cardiovascular Diseases
Heart Block
Arrhythmias, Cardiac
Pathologic Processes