Medical devices are described for performing mapping, ablating, and/or pacing procedures on one or more layers of the cardiac wall via an epicardial approach in a minimally invasive (e.g., orthoscopic) surgical procedure. One of the medical devices described includes a main support member and one or more secondary support members extending outwardly from the main support member having electrodes configured to receive electrical impulses. The secondary support member may include a support pad configured to be removably attached to a corresponding area of the epicardium for holding the medical device in place during a procedure, such as through application of vacuum pressure via a containment dome provided on each secondary support member. Further, an ablating electrode may be slidably disposed along the main support member for transmitting energy to a target site proximate the electrode. Associated methods are also described.