Apparatus and methods for pacing the heart. The apparatus may include, and the methods may involve, an elongated member having: a delivery lumen that is configured to traverse the heart wall, the lumen having a proximal opening for receiving the instrument and a distal opening for deploying the instrument; and an electrically conductive member that is configured to deliver to the heart wall a current that modifies a contraction frequency. The apparatus may include an access opening closure device that has: a distal end that is configured to be disposed interior the heart and contact endocardial tissue adjacent the access opening; and a proximal end that is configured to be disposed exterior the heart and contact heart tissue adjacent the access opening; and an electrode that is configured to discharge electrical energy into the heart wall to change the frequency. The apparatus may include an injectable needle pacing electrode.