An apparatus includes a body assembly, a shaft, and at least one tip member. The shaft extends distally from the body assembly and includes a distal end. The at least one tip member is secured at the distal end of the shaft. The at least one tip member and the distal end of the shaft are sized and configured to fit within a chamber of a heart of a human subject. The at least one tip member includes an atraumatic distal tip and an exterior dilation surface adjacent to the atraumatic distal tip. The atraumatic hollow distal tip may present an angled profile to minimize risk of coring tissue and is configured to deliver electrical energy to tissue for forming an opening through the tissue. The exterior dilation surface is configured to enlarge the opening formed by the atraumatic distal tip.