This pilot study will have a randomized, double-blind, cross-over design. Patients will be randomized to receive either standard biventricular pacing (MPP-OFF) or MPP (MPP-ON) within 4-6 months following the implantation procedure. Each subject will crossover to the other study group after three months. The baseline evaluation should be acquired prior to the device being programmed to the randomized setting. Repeat evaluations will be performed at the end of each 3 month crossover period.