A device for implantation in a left atrial appendage of the heart comprises docking station comprising a radially expansible element that is adjustable between a contracted orientation suitable for transluminal delivery and a deployed orientation configured to anchor within the left atrial appendage and fluidically isolate the left atrial appendage from the left atrium, the docking station also includes a recessed socket accessible from the left atrium through an opening, and a closure coving the opening. A modular active element is configured for detachable engagement within the recessed socket of the docking station. The modular active element comprises a treatment element configured to electrically stimulate heart tissue, thermally stimulate heart tissue, electroporate heart tissue, or deliver a substance into heart tissue or a chamber of the heart, or a sensing element configured to detect a parameter selected from temperature, pressure, electrical signal, heart rate, or respiratory rate.
