T-wave Alternans and Intrathoracic Impedance Measurements
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Congestive Heart Failure
- Sponsor
- Columbia University
- Enrollment
- 9
- Locations
- 1
- Primary Endpoint
- Number of Positive Twave Studies and Concurrent Positive Optivol Measurement
- Status
- Completed
- Last Updated
- 13 years ago
Overview
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.
Investigators
Jose M. Dizon
Assoc Professor of Clinical, Department of Cardiology
Columbia University
Eligibility Criteria
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
Outcomes
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.