Quadripolar CRT-D On Currently Approved Lead SystemS

Inclusion Criteria:

- Subject is medically indicated for implantation with a Boston Scientific (BSC) DYNAGEN
or INOGEN X4 CRT-D (or any future FDA approved BSC X4 CRT-D) and already implanted
with/scheduled to receive a commercially available quadripolar left ventricular lead

- Subject is willing and capable of providing informed consent and participating in all
testing and study visits associated with this investigation at an approved center and
at the intervals defined by this protocol

- Subject is age 18 or above, or of legal age to give informed consent specific to state
and national law

Exclusion Criteria:

- Subject has a known or suspected sensitivity to dexamethasone acetate (DXA)

- Subject is enrolled in any other concurrent study, without prior approval from BSC

- Women of childbearing potential who are or might be pregnant at the time of study
enrollment