Abstract: A steerable catheter system to perform a transseptal puncture procedure comprises a steerable catheter shaft with at least one inner lumen, and an inner element slidably positioned within a shaft lumen, wherein the distal tip of the shaft can be deflected, counter-deflected, rotated, and counter-rotated and wherein the inner element can be deployed or retracted. In one embodiment, a single steerable catheter is capable of performing an intended procedure and a transseptal procedure all in one, wherein the catheter comprises an outer steerable catheter and an inner element which can be deployed to perform a transseptal puncture, and wherein, once the inner element crosses the inter-atrial septum, the catheter itself can slide forward without advancement of the inner element.