A delivery system assembly facilitating deployment of an implantable medical device, the assembly comprising: a handle including at least one control member; an elongate outer tube extending distally from the handle and forming a lumen that extends from a proximal opening thereof at a proximal end of the outer tube to a distal opening thereof at a distal end of the outer tube, the proximal end of the outer tube being coupled to one of the at least one control member of the handle, the outer tube being longitudinally moveable relative to the handle, via the control member, and the outer tube including a distal-most portion having a length along which the lumen is sized to contain an entirety of the medical device therein, the distal opening of the lumen allowing passage of the medical device therethrough for the deployment; an elongate inner member extending within the lumen of the outer tube, the inner member including a proximal end and a distal end, the distal end being configured to conform to a proximal end of the implantable medical device and to engage within the distal-most portion of the outer tube at a location that allows the engaged distal end of the inner member and the entirety of the medical device to be contained within the distal-most portion together; and an articulation sheath surrounding the outer tube in between the handle and the distal-most portion of the outer tube such that the outer tube is longitudinally moveable within the sheath, the sheath including a proximal end, located distal to the handle, a distal end, and a pull-wire member extending between the proximal and distal ends of the sheath, the pull-wire member including a proximal control end and a distal end, the distal end being anchored in proximity to the distal end of the sheath for deflection thereof, and the sheath having an inner diameter that is smaller than an outer diameter of the distal-most portion of the outer tube and an outer diameter of the handle; wherein, when the distal end of the inner member is engaged within the distal-most portion of the outer tube, longitudinal movement of the outer tube, in a distal direction, relative to the articulation sheath, causes similar longitudinal movement of the inner member; and when the outer tube is moved longitudinally in a proximal direction, relative to the handle, the distal end of the inner member is disengaged within the distal-most portion of the outer tube so that the movement of the outer tube is independent of the inner member. a handle including at least one control member; an elongate outer tube extending distally from the handle and forming a lumen that extends from a proximal opening thereof at a proximal end of the outer tube to a distal opening thereof at a distal end of the outer tube, the proximal end of the outer tube being coupled to one of the at least one control member of the handle, the outer tube being longitudinally moveable relative to the handle, via the control member, and the outer tube including a distal-most portion having a length along which the lumen is sized to contain an entirety of the medical device therein, the distal opening of the lumen allowing passage of the medical device therethrough for the deployment; an elongate inner member extending within the lumen of the outer tube, the inner member including a proximal end and a distal end, the distal end being configured to conform to a proximal end of the implantable medical device and to engage within the distal-most portion of the outer tube at a location that allows the engaged distal end of the inner member and the entirety of the medical device to be contained within the distal-most portion together; and an articulation sheath surrounding the outer tube in between the handle and the distal-most portion of the outer tube such that the outer tube is longitudinally moveable within the sheath, the sheath including a proximal end, located distal to the handle, a distal end, and a pull-wire member extending between the proximal and distal ends of the sheath, the pull-wire member including a proximal control end and a distal end, the distal end being anchored in proximity to the distal end of the sheath for deflection thereof, and the sheath having an inner diameter that is smaller than an outer diameter of the distal-most portion of the outer tube and an outer diameter of the handle; wherein, when the distal end of the inner member is engaged within the distal-most portion of the outer tube, longitudinal movement of the outer tube, in a distal direction, relative to the articulation sheath, causes similar longitudinal movement of the inner member; and when the outer tube is moved longitudinally in a proximal direction, relative to the handle, the distal end of the inner member is disengaged within the distal-most portion of the outer tube so that the movement of the outer tube is independent of the inner member.