DEVICE: Corox (04035479112165)

An implantable flexible wire with an electrode, insulated with non-conductive material except at its ends, which serves as an electrical conductor to transmit pacing impulses from an implanted cardiac resynchronization therapy (CRT) pulse generator to the left ventricle of the heart. It may also transmit electrical responses from the heart back to the pacemaker; it is not intended to conduct defibrillation impulses. The electrode end is introduced into a cardiac vein through transvenous approach via the coronary sinus. It is typically impregnated with a steroid (e.g., dexamethasone) intended to elute into the tissues to reduce inflammation.