Devices and methods are provided for performing a medical procedure using a trans-septal approach. The device includes a dilator including a proximal end, a distal end terminating in a distal tip, and a lumen extending between the dilator proximal and distal ends, and a needle device including a proximal end, a distal end sized for introduction into the dilator lumen and terminating in a sharpened distal tip. The needle is movable relative to the dilator to selectively expose the needle device distal tip distally from the dilator lumen and advance the dilator relative to the needle device. The dilator may have a complex tapered shape on its distal tip, e.g., including first and second tapered regions. The needle device may include an inner needle including the sharpened distal tip and an outer tube including a substantially blunt distal end that slidably receives the inner needle.