T-wave Alternans and Intrathoracic Impedance Measurements

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.

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Key information

Conditions

Congestive Heart Failure Arrhythmias Arrhythmias, Cardiac Cardiovascular Diseases Heart Diseases Heart Failure Pathologic Processes Pathological Conditions, Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Columbia University Medical Center

New York, 10032, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

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

Exclusion criteria

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

Treatment and study plan

Congestive heart failure

Other

Spontaneous occurrence of fluid overload.

Primary outcomes

Number of Positive Twave Studies and Concurrent Positive Optivol Measurement

Time frame: upto 3 years

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.

Sponsors and collaborators

Lead sponsor

Columbia University

Other

Collaborators

Medtronic

Registry information

Important dates

Study start: 2008
Primary completion: 2012
Study completion: 2012
First posted: Apr 30, 2008
Registry last updated: Apr 19, 2013

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

Completed