Dynamic Thoracic Impedance as a Marker for Heart Failure Decompensation

Improved metrics derived from the transthoracic impedance (Z) available from implanted
Medtronic devices may provide more sensitive indicators of the state of compensation for
heart failure patients. Quantification of specific data may provide new information that can
improve quality of life for patients and offer vital information to clinicians regarding the
adequacy of inpatient and outpatient assessment and management of acute decompensated heart
failure.

Inclusion Criteria:

- Patients with systolic dysfunction

- Able to provide informed consent

- Have a Medtronic manufactured device with Thoracic Impendence Monitoring capabilities

Exclusion Criteria:

- Patients with severe congestive heart failure who are intubated

- Patients who are oxygen dependent on continuous positive or bilevel positive
ventilation

- Inability to tolerate postural variations due to congestive heart failure or other
medical or surgical condition.Unable to complete proposed testing

- Subjects who cannot giveWill not give written, informed consent on their own behalf