A transseptal needle or punch is described wherein the distal end of the transseptal needle is able to articulate laterally out of the longitudinal axis of the steerable transseptal needle. The transseptal needle includes a blunted distal end configuration that is minimally traumatic. Under control by the user or a computer, the transseptal needle can be articulated to generate various curves with high bending force. The transseptal needle is configured for use with an introducer which can also include side windows.