T-wave Alternans and Intrathoracic Impedance Measurements

NCT00669682 | Completed Results

• 1 other identifier: AAAC5529
• Study Type: observational
• Target: 9
• Locations: 1 country
• Sites: 1

Brief Summary

T-wave alternans is a test that is currently being used to risk stratify patients with structural heart disease for sudden cardiac death. The mechanism of T-wave alternans is unclear, but may share a common abnormality with conditions of cardiac fluid overload such as heart failure, which is altered intracellular calcium handling. Current Medtronic implantable defibrillators have the capability of monitoring cardiac fluid status via transthoracic impedance measurements. The purpose of this study is to determine if a correlation exists between T-wave alternans status and cardiac volume status, as determined by transthoracic impedance measurements. Secondarily, the study seeks to examine the relationship between arrhythmia frequency and T-wave alternans or cardiac volume status.

Conditions

Congestive Heart Failure; Arrhythmias

Outcome Measures

Primary Outcomes (1)

• Number of Positive Twave Studies and Concurrent Positive Optivol Measurement

  We wanted to examine whether positive Optivol status corresponded to a higher likelihood of a positive T wave study. The T wave alternans result is determined by a proprietary device that measures T wave and reports the result as negative, positive, or indeterminate. The Optivol measurement is obtained through transthoracic impedance values in the implanted device. We investigated the correlation between Optivol status and T wave alternans status.

  upto 3 years

Study Arms (1)

Group A

The study group will include Class III to IV heart failure patients followed in the device clinic that have a chronically implanted (more than 90 days) Medtronic biventricular defibrillator with the ability to monitor intrathoracic impedance.

Other: Congestive heart failure

Interventions

Congestive heart failure OTHER

Spontaneous occurrence of fluid overload.

Group A

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Class III or IV heart failure patients

You may qualify if:

• Class III or IV heart failure patients with a chronically implanted Medtronic biventricular defibrillator system capable of monitoring intrathoracic fluid volume.

You may not qualify if:

• no active ischemia or pulmonary edema, atrial fibrillation, complete heart block

Sponsors & Collaborators

• Columbia University: lead
• Medtronic: collaborator

Study Sites (1)

Columbia University Medical Center

New York, New York, 10032, United States

Location

MeSH Terms

Conditions

Heart Failure; Arrhythmias, Cardiac

Condition Hierarchy (Ancestors)

Heart Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Results Point of Contact

• Title: Jose' Dizon, MD
• Organization: Columbia University

jmd11@columbia.edu

212-305-8559

Study Officials

• Jose M Dizon, MD

  Columbia University

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assoc Professor of Clinical, Department of Cardiology

Study Record Dates

• First Submitted: April 28, 2008
• First Posted: April 30, 2008
• Study Start: August 1, 2008
• Primary Completion: April 1, 2012
• Study Completion: April 1, 2012
• Last Updated: April 19, 2013
• Results First Posted: March 28, 2013

Record last verified: 2013-04

Locations

US (1)