Interventional medical systems, devices, and components thereof

An interventional medical system comprising:

• an implantable medical device comprising a housing, and a pacing electrode and a fixation member mounted in proximity to a distal end of the housing, the fixation member comprising a plurality of fingers spaced apart from one another around a perimeter of the housing, wherein each of the plurality of fingers is elastically deformable between a relaxed condition and an extended condition and comprises:
• a fixed end;
• a free end;
• one or more peripheral portions;
• and
• one or more cut-out portions, each cut-out portion of the one or more cut-out portions extending from a fixed end of the cut-out portion to a free end of the cut-out portion,
• wherein each peripheral portion of the one or more peripheral portions frames a respective cut-out portion of the one or more cut-out portions, whereby an inside edge of the peripheral portion is spaced apart from an outside edge of the cut-out portion, and wherein each peripheral portion of the one or more peripheral portions is integral with the respective cut-out portion of the one or more cut-out portions at the fixed end of the respective cut-out portion;
• and
• a delivery tool comprising a deployment tube, the deployment tube including a distal opening and a distal-most portion terminated by the distal opening, the distal-most portion being sized to contain the device and to hold the plurality of fingers in the extended condition.