T-wave Alternans and Intrathoracic Impedance Measurements

Columbia University

Status: Completed

Conditions: Arrhythmias; Congestive Heart Failure

Treatments: Other: Congestive heart failure

Study type: Observational

Funder types: Other; Industry

Identifiers

NCT00669682

AAAC5529

Details and patient eligibility

About

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.

Enrollment: 9 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

9 participants in 1 patient group

Group A

Description:

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.

Treatment:

Other: Congestive heart failure