Assessment of sensor parameter in patients with heart failure.

Evaluate the correlation of specific sensor parameters with clinical reference measurements in patients with heart failure.

Inclusion Criteria:

• COGNIS CRT-D model N119 or N120, functional bipolar leads: RA, RV, and LV lead all implanted for a minimum of 30 days
• Prescribed to optimal pharmacologic therapy for heart failure for at least 30 days prior to enrollment
• Age 18 or above, or of legal age to give informed consent specific to state and national law

Exclusion Criteria:

• Documented HF decompensation, as defined by a hospitalization or greater than a doubling of baseline diuretic dose due to worsening HF, within the last 3 months
• Patients who are pacemaker dependent
• Creatinine ≥ 2.5 mg/dL test within the last 3 months
• Requires assistance walking, for example a cane or walker
• Have an atrial tachyarrhythmia that is permanent or persistent
• Have moderate to severe chronic pulmonary disease as defined by FEV1 < 55% predicted
• Documented life expectancy of less than 6 months
• Patients at an unreasonable risk of not being able to reach the investigational center in case of an emergency, per physician discretion
• Enrolled in any concurrent study

Heart failure patients with an implanted CRT-D