Apparatus and method according to the disclosure relate to minimizing gaps between a substantially planar cardiac-sensing electrode and a shroud member utilizing a so-called interference-fit. For example, a relatively recessed area or aperture formed in an exemplary resin-based shroud member has slightly reduced dimensions relative to the electrode and requires compression forces during assembly (e.g., manually or in an automated process including a press, a tool or other means). The interference-fit promotes a very tight fit (or seal) between the metallic electrode and the resin-based shroud member and, importantly, minimizes gaps. Additionally, discrete interference structures promote fluid tight seals between the electrode and a recess or aperture adapted to receive the electrode.