Systems and methods for transeptal cardiac procedures are disclosed. A method for treating a patient in accordance with a particular embodiment includes positioning a tissue penetrating guidewire adjacent to a cardiac septum, directing pulses of energy to the guidewire, and advancing the guidewire into and through the septum by moving the guidewire in a distal direction in a series of discrete steps. Individual steps can be of a predetermined distance measured outside the patient's body. The method can further include passing a catheter over the guidewire after the guidewire has passed through the septum.