A coaxial transseptal device (43) and methods of piercing a tissue within the heart (24). The coaxial transseptal device (43) includes a piercing device having a shaft with a distal sharpened portion. The coaxial transseptal device (44) also includes a coaxial guide-wire (46) configured to receive the piercing device (44) and move relative thereto. The flexibility of the coaxial guide-wire (46) increases from the proximal end to the distal end.
