Inclusion Criteria:

• Moderate to severe heart failure (NYHA Class III/IV) including left ventricular dysfunction (EF <= 35%) and QRS duration >= 120 ms remaining symptomatic despite stable, optimal heart failure drug therapy.
• Creatinine < 2.5 mg/dL obtained no more than two weeks prior to enrollment.
• Age 18 or above, or of legal age to give informed consent specific to state and national law.
• Willing and capable of providing informed consent, undergoing a device implant, participating in all testing associated with this clinical investigation at an approved clinical investigational center and at the intervals defined by this protocol.

Exclusion Criteria:

• A known hypersensitivity to a 1.0 mg (0.5 mg per electrode) dose of dexamethasone acetate.
• Previous cardiac resynchronization therapy, a coronary venous pace/sense lead or attempted LV lead placement.
• Pre-existing cardioversion/defibrillation leads other than those specified in this investigational plan (unless the investigator intends to replace them with permitted cardioversion/defibrillation leads).
• Requiring dialysis.
• A myocardial infarct, unstable angina, percutaneous coronary intervention, or coronary artery bypass graft during the preceding 30 days prior to enrollment.
• Hypertrophic obstructive cardiomyopathy or infiltrative cardiomyopathy (e.g., amyloidosis, sarcoidosis).
• A documented life expectancy of less than 6 months or expected to undergo heart transplant within 6 months.
• Enrolled in any concurrent study, without prior Guidant written approval, that may confound the results of this study.
• Have a mechanical tricuspid heart valve.