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