A guidewire (220) for perforating the intra-atrial septum of the heart and method for fabricating are disclosed. The guidewire having an elongated body (222), an end section (226), and a tapered distal section (28), with at least a portion of the end section having a first dimension in a first direction transverse to the longitudinal axis of the elongated body that is larger than a second dimension in a second direction transverse to the longitudinal axis, at least a portion of the end section being ovalized (fig.7B).
