Characterization of Cardiac Hemodynamics During MultiSite Pacing

Inclusion Criteria: * Be scheduled to undergo implant of a St Jude Medical CRT-D system with approved standard indication by ESC/EHRA Guidelines * Be in sinus rhythm at the time of enrollment * Have the ability to provide informed consent for study participation and be willing and able to comply with the Clinical Investigation Plan (CIP) described evaluations and follow-up schedule Exclusion Criteria: * Exhibit Cheyne-Stokes respiration * Have persistent or permanent atrial fibrillation * Have complete heart block * Be in NYHA IV functional class * Have a recent myocardial infarction within 40 days prior to enrollment * Have undergone cardiac surgery or coronary revascularization procedure within 3 months prior to enrollment or be scheduled for such procedures in the following 7 months * Have had a recent CVA or TIA within 3 months prior to enrollment * Have had intravenous inotropic support in the last 30 days * Be less than 18 years of age * Be pregnant