Arrhythmias, Congestive Heart Failure
Conditions
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.
Interventions
OTHERCongestive heart failure
Spontaneous occurrence of fluid overload.
Sponsors
Medtronic
Columbia University
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of Positive Twave Studies and Concurrent Positive Optivol Measurement | 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. |
Countries
United States
Participant flow
Recruitment details
9 patients enrolled from device clinic between 8/14/08 and 2/11/11
Participants by arm
| Arm | Count |
|---|---|
| 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. | 9 |
| Total | 9 |
Baseline characteristics
| Characteristic | Group A |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 2 Participants |
| Age, Categorical Between 18 and 65 years | 7 Participants |
| Age Continuous | 60 years STANDARD_DEVIATION 10 |
| Region of Enrollment United States | 9 participants |
| Sex: Female, Male Female | 4 Participants |
| Sex: Female, Male Male | 5 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 9 |
| serious Total, serious adverse events | 0 / 9 |
Outcome results
Primary
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.
Time frame: upto 3 years
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Positive Optivol Status | Number of Positive Twave Studies and Concurrent Positive Optivol Measurement | Positive T wave alternans | 1 participants |
| Positive Optivol Status | Number of Positive Twave Studies and Concurrent Positive Optivol Measurement | Negative T wave alternans | 2 participants |
| Negative Optivol Status | Number of Positive Twave Studies and Concurrent Positive Optivol Measurement | Positive T wave alternans | 1 participants |
| Negative Optivol Status | Number of Positive Twave Studies and Concurrent Positive Optivol Measurement | Negative T wave alternans | 5 participants |